Aggregate in SELECT query
Hi All,
Is it possible to manipulate(add, subtract,...) two fields belonging to two different tables in a SELECT query or JOIN statement.
Ex.
SELECT
<TABLE1>~<FIELD1>
<TABLE1>~<FIELD2>
<TABLE2>~<FIELD1>
<TABLE1>~<FIELD2>
INTO TABLE
<RESULT_TAB>
FROM
<TABLE1>
INNER JOIN
<TABLE2>
ON
<TABLE1>~<FIELD1> = <TABLE2>~<FIELD1> ...
My problem is, while selecting can i add or subtract two fields say <TABLE1><FIELD1> and <TABLE2><FIELD1>.
Regards,
Mustajab.
Hi Mustajab!
IMHO you can't manipulate two fields during the select (in open SQL).
If you are interested in sums (or differences) over all entries, then you can use the aggregation function SUM and make the final calculation with the total of the columns - but not line by line.
Regards,
Christian
Similar Messages
-
How can i use SUM aggregate in select query?
HI,
GURUS,
How can i use SUM function in Select Query and i want to store that value into itab.
for ex:
TABLES: vbap.
types: begin of ty_vbap,
incluse type vbap,
sum type string,
end of ty_vbap.
data: i_vbap type TABLE OF ty_vbap,
w_vbap type ty_vbap.
SELECT sum(posnr) FROM vbap into table i_vbap up to 5 rows.
(or)
SELECT sum(posnr) FROM vbap into table i_vbap group by vbeln.
loop at i_vbap into w_vbap
" which variable have to use to display summed value.
endloop.
if above code is not understandable pleas give ome sample code on above query.
Thank u,
shabeer ahmed.Hi,
Check this sample code.
TABLES SBOOK.
DATA: COUNT TYPE I, SUM TYPE P DECIMALS 2, AVG TYPE F.
DATA: CONNID LIKE SBOOK-CONNID.
SELECT CONNID COUNT( * ) SUM( LUGGWEIGHT ) AVG( LUGGWEIGHT )
INTO (CONNID, COUNT, SUM, AVG)
FROM SBOOK
WHERE
CARRID = 'LH ' AND
FLDATE = '19950228'
GROUP BY CONNID.
WRITE: / CONNID, COUNT, SUM, AVG.
ENDSELECT.
Regards,
Sravanthi -
Select Query failing on a table that has per sec heavy insertions.
Hi
Problem statement
1- We are using 11g as an database.
2- We have a table that is partitioned on the date as range partition.
3- The insertion of data is very high.i.e. several hundreds records per sec. in the current partitioned.
4- The data is continuously going in the current partitioned as and when buffer is full or per sec timer expires.
5-- We have to make also select query on the same table and on the current partitioned say for the latest 500 records.
6- Effecient indexes are also created on the table.
Solutions Tried.
1- After analyzing by tkprof it is observed that select and execute is working fine but fetch is taking too much time to show the out put. Say it takes 1 hour.
2- Using the 11g sql advisior and SPM several baseline is created but the success rate of them is observed also too low.
please suggest any solution to this issue
1- i.e. Redisgn of table.
2- Any better way to quey to fix the fetch issue.
3- Any oracle seetings or parameter changes to fix the fetch issue.
Thanks in advance.
Regards
Vishal SharmaI am uploading the latest stats please let me know how can improve as this is taking 25 minutes
####TKPROF output#########
SQL ID : 2j5w6bv437cak
select almevttbl.AlmEvtId, almevttbl.AlmType, almevttbl.ComponentId,
almevttbl.TimeStamp, almevttbl.Severity, almevttbl.State,
almevttbl.Category, almevttbl.CauseCode, almevttbl.UnitType,
almevttbl.UnitId, almevttbl.UnitName, almevttbl.ServerName,
almevttbl.StrParam, almevttbl.ExtraStrParam, almevttbl.ExtraStrParam2,
almevttbl.ExtraStrParam3, almevttbl.ParentCustId, almevttbl.ExtraParam1,
almevttbl.ExtraParam2, almevttbl.ExtraParam3,almevttbl.ExtraParam4,
almevttbl.ExtraParam5, almevttbl.SRCIPADDRFAMILY,almevttbl.SrcIPAddress11,
almevttbl.SrcIPAddress12,almevttbl.SrcIPAddress13,almevttbl.SrcIPAddress14,
almevttbl.DESTIPADDRFAMILY,almevttbl.DestIPAddress11,
almevttbl.DestIPAddress12,almevttbl.DestIPAddress13,
almevttbl.DestIPAddress14, almevttbl.DestPort, almevttbl.SrcPort,
almevttbl.SessionDir, almevttbl.CustomerId, almevttbl.ProfileId,
almevttbl.ParentProfileId, almevttbl.CustomerName, almevttbl.AttkDir,
almevttbl.SubCategory, almevttbl.RiskCategory, almevttbl.AssetValue,
almevttbl.IPSAction, almevttbl.l4Protocol,almevttbl.ExtraStrParam4 ,
almevttbl.ExtraStrParam5,almevttbl.username,almevttbl.ExtraStrParam6,
IpAddrFamily1,IPAddrValue11,IPAddrValue12,IPAddrValue13,IPAddrValue14,
IpAddrFamily2,IPAddrValue21,IPAddrValue22,IPAddrValue23,IPAddrValue24
FROM
AlmEvtTbl PARTITION(ALMEVTTBLP20100323) WHERE AlmEvtId IN ( SELECT * FROM
( SELECT /*+ FIRST_ROWS(1000) INDEX (AlmEvtTbl AlmEvtTbl_Index) */AlmEvtId
FROM AlmEvtTbl PARTITION(ALMEVTTBLP20100323) where ((AlmEvtTbl.Customerid
= 0 or AlmEvtTbl.ParentCustId = 0)) ORDER BY AlmEvtTbl.TIMESTAMP DESC)
WHERE ROWNUM < 602) order by timestamp desc
call count cpu elapsed disk query current rows
Parse 1 0.10 0.17 0 0 0 0
Execute 1 0.00 0.00 0 0 0 0
Fetch 42 1348.25 1521.24 1956 39029545 0 601
total 44 1348.35 1521.41 1956 39029545 0 601
Misses in library cache during parse: 1
Optimizer mode: FIRST_ROWS
Parsing user id: 82
Rows Row Source Operation
601 PARTITION RANGE SINGLE PARTITION: 24 24 (cr=39029545 pr=1956 pw=1956 time=11043 us cost=0 size=7426 card=1)
601 TABLE ACCESS BY LOCAL INDEX ROWID ALMEVTTBL PARTITION: 24 24 (cr=39029545 pr=1956 pw=1956 time=11030 us cost=0 size=7426 card=1)
601 INDEX FULL SCAN ALMEVTTBL_INDEX PARTITION: 24 24 (cr=39029377 pr=1956 pw=1956 time=11183 us cost=0 size=0 card=1)(object id 72557)
601 FILTER (cr=39027139 pr=0 pw=0 time=0 us)
169965204 COUNT STOPKEY (cr=39027139 pr=0 pw=0 time=24859073 us)
169965204 VIEW (cr=39027139 pr=0 pw=0 time=17070717 us cost=0 size=13 card=1)
169965204 PARTITION RANGE SINGLE PARTITION: 24 24 (cr=39027139 pr=0 pw=0 time=13527031 us cost=0 size=48 card=1)
169965204 TABLE ACCESS BY LOCAL INDEX ROWID ALMEVTTBL PARTITION: 24 24 (cr=39027139 pr=0 pw=0 time=10299895 us cost=0 size=48 card=1)
169965204 INDEX FULL SCAN ALMEVTTBL_INDEX PARTITION: 24 24 (cr=1131414 pr=0 pw=0 time=3222624 us cost=0 size=0 card=1)(object id 72557)
Elapsed times include waiting on following events:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
SQL*Net message to client 42 0.00 0.00
SQL*Net message from client 42 11.54 133.54
db file sequential read 1956 0.20 28.00
latch free 21 0.00 0.01
latch: cache buffers chains 9 0.01 0.02
SQL ID : 0ushr863b7z39
SELECT /* OPT_DYN_SAMP */ /*+ ALL_ROWS IGNORE_WHERE_CLAUSE
NO_PARALLEL(SAMPLESUB) opt_param('parallel_execution_enabled', 'false')
NO_PARALLEL_INDEX(SAMPLESUB) NO_SQL_TUNE */ NVL(SUM(C1),0), NVL(SUM(C2),0)
FROM
(SELECT /*+ IGNORE_WHERE_CLAUSE NO_PARALLEL("PLAN_TABLE") FULL("PLAN_TABLE")
NO_PARALLEL_INDEX("PLAN_TABLE") */ 1 AS C1, CASE WHEN
"PLAN_TABLE"."STATEMENT_ID"=:B1 THEN 1 ELSE 0 END AS C2 FROM
"SYS"."PLAN_TABLE$" "PLAN_TABLE") SAMPLESUB
call count cpu elapsed disk query current rows
Parse 1 0.00 0.00 0 0 0 0
Execute 1 0.00 0.00 0 0 0 0
Fetch 1 0.00 0.01 1 3 0 1
total 3 0.00 0.01 1 3 0 1
Misses in library cache during parse: 1
Misses in library cache during execute: 1
Optimizer mode: ALL_ROWS
Parsing user id: 82 (recursive depth: 1)
Rows Row Source Operation
1 SORT AGGREGATE (cr=3 pr=1 pw=1 time=0 us)
0 TABLE ACCESS FULL PLAN_TABLE$ (cr=3 pr=1 pw=1 time=0 us cost=29 size=138856 card=8168)
Elapsed times include waiting on following events:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
db file sequential read 1 0.01 0.01
SQL ID : bjkdb51at8dnb
EXPLAIN PLAN SET STATEMENT_ID='PLUS30350011' FOR select almevttbl.AlmEvtId,
almevttbl.AlmType, almevttbl.ComponentId, almevttbl.TimeStamp,
almevttbl.Severity, almevttbl.State, almevttbl.Category,
almevttbl.CauseCode, almevttbl.UnitType, almevttbl.UnitId,
almevttbl.UnitName, almevttbl.ServerName, almevttbl.StrParam,
almevttbl.ExtraStrParam, almevttbl.ExtraStrParam2, almevttbl.ExtraStrParam3,
almevttbl.ParentCustId, almevttbl.ExtraParam1, almevttbl.ExtraParam2,
almevttbl.ExtraParam3,almevttbl.ExtraParam4,almevttbl.ExtraParam5,
almevttbl.SRCIPADDRFAMILY,almevttbl.SrcIPAddress11,almevttbl.SrcIPAddress12,
almevttbl.SrcIPAddress13,almevttbl.SrcIPAddress14,
almevttbl.DESTIPADDRFAMILY,almevttbl.DestIPAddress11,
almevttbl.DestIPAddress12,almevttbl.DestIPAddress13,
almevttbl.DestIPAddress14, almevttbl.DestPort, almevttbl.SrcPort,
almevttbl.SessionDir, almevttbl.CustomerId, almevttbl.ProfileId,
almevttbl.ParentProfileId, almevttbl.CustomerName, almevttbl.AttkDir,
almevttbl.SubCategory, almevttbl.RiskCategory, almevttbl.AssetValue,
almevttbl.IPSAction, almevttbl.l4Protocol,almevttbl.ExtraStrParam4 ,
almevttbl.ExtraStrParam5,almevttbl.username,almevttbl.ExtraStrParam6,
IpAddrFamily1,IPAddrValue11,IPAddrValue12,IPAddrValue13,IPAddrValue14,
IpAddrFamily2,IPAddrValue21,IPAddrValue22,IPAddrValue23,IPAddrValue24 FROM
AlmEvtTbl PARTITION(ALMEVTTBLP20100323) WHERE AlmEvtId IN ( SELECT * FROM
( SELECT /*+ FIRST_ROWS(1000) INDEX (AlmEvtTbl AlmEvtTbl_Index) */AlmEvtId
FROM AlmEvtTbl PARTITION(ALMEVTTBLP20100323) where ((AlmEvtTbl.Customerid
= 0 or AlmEvtTbl.ParentCustId = 0)) ORDER BY AlmEvtTbl.TIMESTAMP DESC)
WHERE ROWNUM < 602) order by timestamp desc
call count cpu elapsed disk query current rows
Parse 1 0.28 0.26 0 0 0 0
Execute 1 0.01 0.00 0 0 0 0
Fetch 0 0.00 0.00 0 0 0 0
total 2 0.29 0.27 0 0 0 0
Misses in library cache during parse: 1
Optimizer mode: FIRST_ROWS
Parsing user id: 82
Elapsed times include waiting on following events:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
SQL*Net message to client 1 0.00 0.00
SQL*Net message from client 1 0.00 0.00
OVERALL TOTALS FOR ALL NON-RECURSIVE STATEMENTS
call count cpu elapsed disk query current rows
Parse 13 0.71 0.96 3 10 0 0
Execute 14 0.20 0.29 4 304 26 21
Fetch 92 2402.17 2714.85 3819 70033708 0 1255
total 119 2403.09 2716.10 3826 70034022 26 1276
Misses in library cache during parse: 10
Misses in library cache during execute: 6
Elapsed times include waiting on following events:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
SQL*Net message to client 49 0.00 0.00
SQL*Net message from client 48 29.88 163.43
db file sequential read 1966 0.20 28.10
latch free 21 0.00 0.01
latch: cache buffers chains 9 0.01 0.02
latch: session allocation 1 0.00 0.00
OVERALL TOTALS FOR ALL RECURSIVE STATEMENTS
call count cpu elapsed disk query current rows
Parse 940 0.51 0.73 1 2 38 0
Execute 3263 1.93 2.62 7 1998 43 23
Fetch 6049 1.32 4.41 214 12858 36 13724
total 10252 3.78 7.77 222 14858 117 13747
Misses in library cache during parse: 172
Misses in library cache during execute: 168
Elapsed times include waiting on following events:
Event waited on Times Max. Wait Total Waited
---------------------------------------- Waited ---------- ------------
db file sequential read 88 0.04 0.62
latch: shared pool 8 0.00 0.00
latch: row cache objects 2 0.00 0.00
latch free 1 0.00 0.00
latch: session allocation 1 0.00 0.00
34 user SQL statements in session.
3125 internal SQL statements in session.
3159 SQL statements in session.
Trace file: ora11g_ora_2064.trc
Trace file compatibility: 11.01.00
Sort options: default
6 sessions in tracefile.
98 user SQL statements in trace file.
9111 internal SQL statements in trace file.
3159 SQL statements in trace file.
89 unique SQL statements in trace file.
30341 lines in trace file.
6810 elapsed seconds in trace file.
###################################### AutoTrace Output#################
Statistics
3901 recursive calls
0 db block gets
39030275 consistent gets
1970 physical reads
140 redo size
148739 bytes sent via SQL*Net to client
860 bytes received via SQL*Net from client
42 SQL*Net roundtrips to/from client
73 sorts (memory)
0 sorts (disk)
601 rows processed -
SELECT query takes too much time! Y?
Plz find my SELECT query below:
select w~mandt
wvbeln wposnr wmeins wmatnr wwerks wnetwr
wkwmeng wvrkme wmatwa wcharg w~pstyv
wposar wprodh wgrkor wantlf wkztlf wlprio
wvstel wroute wumvkz wumvkn wabgru wuntto
wawahr werdat werzet wfixmg wprctr wvpmat
wvpwrk wmvgr1 wmvgr2 wmvgr3 wmvgr4 wmvgr5
wbedae wcuobj w~mtvfp
xetenr xwmeng xbmeng xettyp xwepos xabart
x~edatu
xtddat xmbdat xlddat xwadat xabruf xetart
x~ezeit
into table t_vbap
from vbap as w
inner join vbep as x on xvbeln = wvbeln and
xposnr = wposnr and
xmandt = wmandt
where
( ( werdat > pre_dat ) and ( werdat <= w_date ) ) and
( ( ( erdat > pre_dat and erdat < p_syndt ) or
( erdat = p_syndt and erzet <= p_syntm ) ) ) and
w~matnr in s_matnr and
w~pstyv in s_itmcat and
w~lfrel in s_lfrel and
w~abgru = ' ' and
w~kwmeng > 0 and
w~mtvfp in w_mtvfp and
x~ettyp in w_ettyp and
x~bdart in s_req_tp and
x~plart in s_pln_tp and
x~etart in s_etart and
x~abart in s_abart and
( ( xlifsp in s_lifsp ) or ( xlifsp = ' ' ) ).
The problem: It takes too much time while executing this statement.
Could anybody change this statement and help me out to reduce the DB Access time?
ThxWays of Performance Tuning
1. Selection Criteria
2. Select Statements
Select Queries
SQL Interface
Aggregate Functions
For all Entries
Select Over more than one internal table
Selection Criteria
1. Restrict the data to the selection criteria itself, rather than filtering it out using the ABAP code using CHECK statement.
2. Select with selection list.
SELECT * FROM SBOOK INTO SBOOK_WA.
CHECK: SBOOK_WA-CARRID = 'LH' AND
SBOOK_WA-CONNID = '0400'.
ENDSELECT.
The above code can be much more optimized by the code written below which avoids CHECK, selects with selection list
SELECT CARRID CONNID FLDATE BOOKID FROM SBOOK INTO TABLE T_SBOOK
WHERE SBOOK_WA-CARRID = 'LH' AND
SBOOK_WA-CONNID = '0400'.
Select Statements Select Queries
1. Avoid nested selects
SELECT * FROM EKKO INTO EKKO_WA.
SELECT * FROM EKAN INTO EKAN_WA
WHERE EBELN = EKKO_WA-EBELN.
ENDSELECT.
ENDSELECT.
The above code can be much more optimized by the code written below.
SELECT PF1 PF2 FF3 FF4 INTO TABLE ITAB
FROM EKKO AS P INNER JOIN EKAN AS F
ON PEBELN = FEBELN.
Note: A simple SELECT loop is a single database access whose result is passed to the ABAP program line by line. Nested SELECT loops mean that the number of accesses in the inner loop is multiplied by the number of accesses in the outer loop. One should therefore use nested SELECT loops only if the selection in the outer loop contains very few lines or the outer loop is a SELECT SINGLE statement.
2. Select all the records in a single shot using into table clause of select statement rather than to use Append statements.
SELECT * FROM SBOOK INTO SBOOK_WA.
CHECK: SBOOK_WA-CARRID = 'LH' AND
SBOOK_WA-CONNID = '0400'.
ENDSELECT.
The above code can be much more optimized by the code written below which avoids CHECK, selects with selection list and puts the data in one shot using into table
SELECT CARRID CONNID FLDATE BOOKID FROM SBOOK INTO TABLE T_SBOOK
WHERE SBOOK_WA-CARRID = 'LH' AND
SBOOK_WA-CONNID = '0400'.
3. When a base table has multiple indices, the where clause should be in the order of the index, either a primary or a secondary index.
To choose an index, the optimizer checks the field names specified in the where clause and then uses an index that has the same order of the fields. In certain scenarios, it is advisable to check whether a new index can speed up the performance of a program. This will come handy in programs that access data from the finance tables.
4. For testing existence, use Select.. Up to 1 rows statement instead of a Select-Endselect-loop with an Exit.
SELECT * FROM SBOOK INTO SBOOK_WA
UP TO 1 ROWS
WHERE CARRID = 'LH'.
ENDSELECT.
The above code is more optimized as compared to the code mentioned below for testing existence of a record.
SELECT * FROM SBOOK INTO SBOOK_WA
WHERE CARRID = 'LH'.
EXIT.
ENDSELECT.
5. Use Select Single if all primary key fields are supplied in the Where condition .
If all primary key fields are supplied in the Where conditions you can even use Select Single.
Select Single requires one communication with the database system, whereas Select-Endselect needs two.
Select Statements SQL Interface
1. Use column updates instead of single-row updates
to update your database tables.
SELECT * FROM SFLIGHT INTO SFLIGHT_WA.
SFLIGHT_WA-SEATSOCC =
SFLIGHT_WA-SEATSOCC - 1.
UPDATE SFLIGHT FROM SFLIGHT_WA.
ENDSELECT.
The above mentioned code can be more optimized by using the following code
UPDATE SFLIGHT
SET SEATSOCC = SEATSOCC - 1.
2. For all frequently used Select statements, try to use an index.
SELECT * FROM SBOOK CLIENT SPECIFIED INTO SBOOK_WA
WHERE CARRID = 'LH'
AND CONNID = '0400'.
ENDSELECT.
The above mentioned code can be more optimized by using the following code
SELECT * FROM SBOOK CLIENT SPECIFIED INTO SBOOK_WA
WHERE MANDT IN ( SELECT MANDT FROM T000 )
AND CARRID = 'LH'
AND CONNID = '0400'.
ENDSELECT.
3. Using buffered tables improves the performance considerably.
Bypassing the buffer increases the network considerably
SELECT SINGLE * FROM T100 INTO T100_WA
BYPASSING BUFFER
WHERE SPRSL = 'D'
AND ARBGB = '00'
AND MSGNR = '999'.
The above mentioned code can be more optimized by using the following code
SELECT SINGLE * FROM T100 INTO T100_WA
WHERE SPRSL = 'D'
AND ARBGB = '00'
AND MSGNR = '999'.
Select Statements Aggregate Functions
If you want to find the maximum, minimum, sum and average value or the count of a database column, use a select list with aggregate functions instead of computing the aggregates yourself.
Some of the Aggregate functions allowed in SAP are MAX, MIN, AVG, SUM, COUNT, COUNT( * )
Consider the following extract.
Maxno = 0.
Select * from zflight where airln = LF and cntry = IN.
Check zflight-fligh > maxno.
Maxno = zflight-fligh.
Endselect.
The above mentioned code can be much more optimized by using the following code.
Select max( fligh ) from zflight into maxno where airln = LF and cntry = IN.
Select Statements For All Entries
The for all entries creates a where clause, where all the entries in the driver table are combined with OR. If the number of entries in the driver table is larger than rsdb/max_blocking_factor, several similar SQL statements are executed to limit the length of the WHERE clause.
The plus
Large amount of data
Mixing processing and reading of data
Fast internal reprocessing of data
Fast
The Minus
Difficult to program/understand
Memory could be critical (use FREE or PACKAGE size)
Points to be must considered FOR ALL ENTRIES
Check that data is present in the driver table
Sorting the driver table
Removing duplicates from the driver table
Consider the following piece of extract
Loop at int_cntry.
Select single * from zfligh into int_fligh
where cntry = int_cntry-cntry.
Append int_fligh.
Endloop.
The above mentioned can be more optimized by using the following code.
Sort int_cntry by cntry.
Delete adjacent duplicates from int_cntry.
If NOT int_cntry[] is INITIAL.
Select * from zfligh appending table int_fligh
For all entries in int_cntry
Where cntry = int_cntry-cntry.
Endif.
Select Statements Select Over more than one Internal table
1. Its better to use a views instead of nested Select statements.
SELECT * FROM DD01L INTO DD01L_WA
WHERE DOMNAME LIKE 'CHAR%'
AND AS4LOCAL = 'A'.
SELECT SINGLE * FROM DD01T INTO DD01T_WA
WHERE DOMNAME = DD01L_WA-DOMNAME
AND AS4LOCAL = 'A'
AND AS4VERS = DD01L_WA-AS4VERS
AND DDLANGUAGE = SY-LANGU.
ENDSELECT.
The above code can be more optimized by extracting all the data from view DD01V_WA
SELECT * FROM DD01V INTO DD01V_WA
WHERE DOMNAME LIKE 'CHAR%'
AND DDLANGUAGE = SY-LANGU.
ENDSELECT
2. To read data from several logically connected tables use a join instead of nested Select statements. Joins are preferred only if all the primary key are available in WHERE clause for the tables that are joined. If the primary keys are not provided in join the Joining of tables itself takes time.
SELECT * FROM EKKO INTO EKKO_WA.
SELECT * FROM EKAN INTO EKAN_WA
WHERE EBELN = EKKO_WA-EBELN.
ENDSELECT.
ENDSELECT.
The above code can be much more optimized by the code written below.
SELECT PF1 PF2 FF3 FF4 INTO TABLE ITAB
FROM EKKO AS P INNER JOIN EKAN AS F
ON PEBELN = FEBELN.
3. Instead of using nested Select loops it is often better to use subqueries.
SELECT * FROM SPFLI
INTO TABLE T_SPFLI
WHERE CITYFROM = 'FRANKFURT'
AND CITYTO = 'NEW YORK'.
SELECT * FROM SFLIGHT AS F
INTO SFLIGHT_WA
FOR ALL ENTRIES IN T_SPFLI
WHERE SEATSOCC < F~SEATSMAX
AND CARRID = T_SPFLI-CARRID
AND CONNID = T_SPFLI-CONNID
AND FLDATE BETWEEN '19990101' AND '19990331'.
ENDSELECT.
The above mentioned code can be even more optimized by using subqueries instead of for all entries.
SELECT * FROM SFLIGHT AS F INTO SFLIGHT_WA
WHERE SEATSOCC < F~SEATSMAX
AND EXISTS ( SELECT * FROM SPFLI
WHERE CARRID = F~CARRID
AND CONNID = F~CONNID
AND CITYFROM = 'FRANKFURT'
AND CITYTO = 'NEW YORK' )
AND FLDATE BETWEEN '19990101' AND '19990331'.
ENDSELECT.
1. Table operations should be done using explicit work areas rather than via header lines.
READ TABLE ITAB INTO WA WITH KEY K = 'X BINARY SEARCH.
IS MUCH FASTER THAN USING
READ TABLE ITAB INTO WA WITH KEY K = 'X'.
If TAB has n entries, linear search runs in O( n ) time, whereas binary search takes only O( log2( n ) ).
2. Always try to use binary search instead of linear search. But dont forget to sort your internal table before that.
READ TABLE ITAB INTO WA WITH KEY K = 'X'. IS FASTER THAN USING
READ TABLE ITAB INTO WA WITH KEY (NAME) = 'X'.
3. A dynamic key access is slower than a static one, since the key specification must be evaluated at runtime.
4. A binary search using secondary index takes considerably less time.
5. LOOP ... WHERE is faster than LOOP/CHECK because LOOP ... WHERE evaluates the specified condition internally.
LOOP AT ITAB INTO WA WHERE K = 'X'.
ENDLOOP.
The above code is much faster than using
LOOP AT ITAB INTO WA.
CHECK WA-K = 'X'.
ENDLOOP.
6. Modifying selected components using MODIFY itab TRANSPORTING f1 f2.. accelerates the task of updating a line of an internal table.
WA-DATE = SY-DATUM.
MODIFY ITAB FROM WA INDEX 1 TRANSPORTING DATE.
The above code is more optimized as compared to
WA-DATE = SY-DATUM.
MODIFY ITAB FROM WA INDEX 1.
7. Accessing the table entries directly in a "LOOP ... ASSIGNING ..." accelerates the task of updating a set of lines of an internal table considerably
Modifying selected components only makes the program faster as compared to Modifying all lines completely.
e.g,
LOOP AT ITAB ASSIGNING <WA>.
I = SY-TABIX MOD 2.
IF I = 0.
<WA>-FLAG = 'X'.
ENDIF.
ENDLOOP.
The above code works faster as compared to
LOOP AT ITAB INTO WA.
I = SY-TABIX MOD 2.
IF I = 0.
WA-FLAG = 'X'.
MODIFY ITAB FROM WA.
ENDIF.
ENDLOOP.
8. If collect semantics is required, it is always better to use to COLLECT rather than READ BINARY and then ADD.
LOOP AT ITAB1 INTO WA1.
READ TABLE ITAB2 INTO WA2 WITH KEY K = WA1-K BINARY SEARCH.
IF SY-SUBRC = 0.
ADD: WA1-VAL1 TO WA2-VAL1,
WA1-VAL2 TO WA2-VAL2.
MODIFY ITAB2 FROM WA2 INDEX SY-TABIX TRANSPORTING VAL1 VAL2.
ELSE.
INSERT WA1 INTO ITAB2 INDEX SY-TABIX.
ENDIF.
ENDLOOP.
The above code uses BINARY SEARCH for collect semantics. READ BINARY runs in O( log2(n) ) time. The above piece of code can be more optimized by
LOOP AT ITAB1 INTO WA.
COLLECT WA INTO ITAB2.
ENDLOOP.
SORT ITAB2 BY K.
COLLECT, however, uses a hash algorithm and is therefore independent
of the number of entries (i.e. O(1)) .
9. "APPEND LINES OF itab1 TO itab2" accelerates the task of appending a table to another table considerably as compared to LOOP-APPEND-ENDLOOP.
APPEND LINES OF ITAB1 TO ITAB2.
This is more optimized as compared to
LOOP AT ITAB1 INTO WA.
APPEND WA TO ITAB2.
ENDLOOP.
10. DELETE ADJACENT DUPLICATES accelerates the task of deleting duplicate entries considerably as compared to READ-LOOP-DELETE-ENDLOOP.
DELETE ADJACENT DUPLICATES FROM ITAB COMPARING K.
This is much more optimized as compared to
READ TABLE ITAB INDEX 1 INTO PREV_LINE.
LOOP AT ITAB FROM 2 INTO WA.
IF WA = PREV_LINE.
DELETE ITAB.
ELSE.
PREV_LINE = WA.
ENDIF.
ENDLOOP.
11. "DELETE itab FROM ... TO ..." accelerates the task of deleting a sequence of lines considerably as compared to DO -DELETE-ENDDO.
DELETE ITAB FROM 450 TO 550.
This is much more optimized as compared to
DO 101 TIMES.
DELETE ITAB INDEX 450.
ENDDO.
12. Copying internal tables by using ITAB2[ ] = ITAB1[ ] as compared to LOOP-APPEND-ENDLOOP.
ITAB2[] = ITAB1[].
This is much more optimized as compared to
REFRESH ITAB2.
LOOP AT ITAB1 INTO WA.
APPEND WA TO ITAB2.
ENDLOOP.
13. Specify the sort key as restrictively as possible to run the program faster.
SORT ITAB BY K. makes the program runs faster as compared to SORT ITAB.
Internal Tables contd
Hashed and Sorted tables
1. For single read access hashed tables are more optimized as compared to sorted tables.
2. For partial sequential access sorted tables are more optimized as compared to hashed tables
Hashed And Sorted Tables
Point # 1
Consider the following example where HTAB is a hashed table and STAB is a sorted table
DO 250 TIMES.
N = 4 * SY-INDEX.
READ TABLE HTAB INTO WA WITH TABLE KEY K = N.
IF SY-SUBRC = 0.
ENDIF.
ENDDO.
This runs faster for single read access as compared to the following same code for sorted table
DO 250 TIMES.
N = 4 * SY-INDEX.
READ TABLE STAB INTO WA WITH TABLE KEY K = N.
IF SY-SUBRC = 0.
ENDIF.
ENDDO.
Point # 2
Similarly for Partial Sequential access the STAB runs faster as compared to HTAB
LOOP AT STAB INTO WA WHERE K = SUBKEY.
ENDLOOP.
This runs faster as compared to
LOOP AT HTAB INTO WA WHERE K = SUBKEY.
ENDLOOP. -
Regarding to perform in select query
could any tell the select query in this piece of code would affect the performance of the programe
DATA: BEGIN OF OUTREC,
BANKS LIKE BNKA-BANKS,
BANKL LIKE BNKA-BANKL,
BANKA LIKE BNKA-BANKA,
PROVZ LIKE BNKA-PROVZ, "Region (State, Province, County)
BRNCH LIKE BNKA-BRNCH,
STRAS LIKE BNKA-STRAS,
ORT01 LIKE BNKA-ORT01,
SWIFT LIKE BNKA-SWIFT,
END OF OUTREC.
OPEN DATASET P_OUTPUT FOR OUTPUT IN TEXT MODE.
IF SY-SUBRC NE 0. EXIT. ENDIF.
SELECT * FROM BNKA
WHERE BANKS EQ P_BANKS
AND LOEVM NE 'X'
AND XPGRO NE 'X'
ORDER BY BANKS BANKL.
PERFORM TRANSFER_DATA.
ENDSELECT.
CLOSE DATASET P_OUTPUT.
*& Transfer the data to the output file
FORM TRANSFER_DATA.
OUTREC-BANKS = BNKA-BANKS.
OUTREC-BANKL = BNKA-BANKL.
OUTREC-BANKA = BNKA-BANKA.
OUTREC-PROVZ = BNKA-PROVZ.
OUTREC-BRNCH = BNKA-BRNCH.
OUTREC-STRAS = BNKA-STRAS.
OUTREC-ORT01 = BNKA-ORT01.
OUTREC-SWIFT = BNKA-SWIFT.
TRANSFER OUTREC TO P_OUTPUT.
ENDFORM. " READ_IN_DATAHi
Ways of Performance Tuning
1. Selection Criteria
2. Select Statements
Select Queries
SQL Interface
Aggregate Functions
For all Entries
Select Over more than one Internal table
Selection Criteria
1. Restrict the data to the selection criteria itself, rather than filtering it out using the ABAP code using CHECK statement.
2. Select with selection list.
Points # 1/2
SELECT * FROM SBOOK INTO SBOOK_WA.
CHECK: SBOOK_WA-CARRID = 'LH' AND
SBOOK_WA-CONNID = '0400'.
ENDSELECT.
The above code can be much more optimized by the code written below which avoids CHECK, selects with selection list
SELECT CARRID CONNID FLDATE BOOKID FROM SBOOK INTO TABLE T_SBOOK
WHERE SBOOK_WA-CARRID = 'LH' AND
SBOOK_WA-CONNID = '0400'.
Select Statements Select Queries
1. Avoid nested selects
2. Select all the records in a single shot using into table clause of select statement rather than to use Append statements.
3. When a base table has multiple indices, the where clause should be in the order of the index, either a primary or a secondary index.
4. For testing existence , use Select.. Up to 1 rows statement instead of a Select-Endselect-loop with an Exit.
5. Use Select Single if all primary key fields are supplied in the Where condition .
Point # 1
SELECT * FROM EKKO INTO EKKO_WA.
SELECT * FROM EKAN INTO EKAN_WA
WHERE EBELN = EKKO_WA-EBELN.
ENDSELECT.
ENDSELECT.
The above code can be much more optimized by the code written below.
SELECT PF1 PF2 FF3 FF4 INTO TABLE ITAB
FROM EKKO AS P INNER JOIN EKAN AS F
ON PEBELN = FEBELN.
Note: A simple SELECT loop is a single database access whose result is passed to the ABAP program line by line. Nested SELECT loops mean that the number of accesses in the inner loop is multiplied by the number of accesses in the outer loop. One should therefore use nested SELECT loops only if the selection in the outer loop contains very few lines or the outer loop is a SELECT SINGLE statement.
Point # 2
SELECT * FROM SBOOK INTO SBOOK_WA.
CHECK: SBOOK_WA-CARRID = 'LH' AND
SBOOK_WA-CONNID = '0400'.
ENDSELECT.
The above code can be much more optimized by the code written below which avoids CHECK, selects with selection list and puts the data in one shot using into table
SELECT CARRID CONNID FLDATE BOOKID FROM SBOOK INTO TABLE T_SBOOK
WHERE SBOOK_WA-CARRID = 'LH' AND
SBOOK_WA-CONNID = '0400'.
Point # 3
To choose an index, the optimizer checks the field names specified in the where clause and then uses an index that has the same order of the fields . In certain scenarios, it is advisable to check whether a new index can speed up the performance of a program. This will come handy in programs that access data from the finance tables.
Point # 4
SELECT * FROM SBOOK INTO SBOOK_WA
UP TO 1 ROWS
WHERE CARRID = 'LH'.
ENDSELECT.
The above code is more optimized as compared to the code mentioned below for testing existence of a record.
SELECT * FROM SBOOK INTO SBOOK_WA
WHERE CARRID = 'LH'.
EXIT.
ENDSELECT.
Point # 5
If all primary key fields are supplied in the Where condition you can even use Select Single.
Select Single requires one communication with the database system, whereas Select-Endselect needs two.
Select Statements contd.. SQL Interface
1. Use column updates instead of single-row updates
to update your database tables.
2. For all frequently used Select statements, try to use an index.
3. Using buffered tables improves the performance considerably.
Point # 1
SELECT * FROM SFLIGHT INTO SFLIGHT_WA.
SFLIGHT_WA-SEATSOCC =
SFLIGHT_WA-SEATSOCC - 1.
UPDATE SFLIGHT FROM SFLIGHT_WA.
ENDSELECT.
The above mentioned code can be more optimized by using the following code
UPDATE SFLIGHT
SET SEATSOCC = SEATSOCC - 1.
Point # 2
SELECT * FROM SBOOK CLIENT SPECIFIED INTO SBOOK_WA
WHERE CARRID = 'LH'
AND CONNID = '0400'.
ENDSELECT.
The above mentioned code can be more optimized by using the following code
SELECT * FROM SBOOK CLIENT SPECIFIED INTO SBOOK_WA
WHERE MANDT IN ( SELECT MANDT FROM T000 )
AND CARRID = 'LH'
AND CONNID = '0400'.
ENDSELECT.
Point # 3
Bypassing the buffer increases the network considerably
SELECT SINGLE * FROM T100 INTO T100_WA
BYPASSING BUFFER
WHERE SPRSL = 'D'
AND ARBGB = '00'
AND MSGNR = '999'.
The above mentioned code can be more optimized by using the following code
SELECT SINGLE * FROM T100 INTO T100_WA
WHERE SPRSL = 'D'
AND ARBGB = '00'
AND MSGNR = '999'.
Select Statements contd Aggregate Functions
If you want to find the maximum, minimum, sum and average value or the count of a database column, use a select list with aggregate functions instead of computing the aggregates yourself.
Some of the Aggregate functions allowed in SAP are MAX, MIN, AVG, SUM, COUNT, COUNT( * )
Consider the following extract.
Maxno = 0.
Select * from zflight where airln = LF and cntry = IN.
Check zflight-fligh > maxno.
Maxno = zflight-fligh.
Endselect.
The above mentioned code can be much more optimized by using the following code.
Select max( fligh ) from zflight into maxno where airln = LF and cntry = IN.
Select Statements contd For All Entries
The for all entries creates a where clause, where all the entries in the driver table are combined with OR. If the number of entries in the driver table is larger than rsdb/max_blocking_factor, several similar SQL statements are executed to limit the length of the WHERE clause.
The plus
Large amount of data
Mixing processing and reading of data
Fast internal reprocessing of data
Fast
The Minus
Difficult to program/understand
Memory could be critical (use FREE or PACKAGE size)
Points to be must considered FOR ALL ENTRIES
Check that data is present in the driver table
Sorting the driver table
Removing duplicates from the driver table
Consider the following piece of extract
Loop at int_cntry.
Select single * from zfligh into int_fligh
where cntry = int_cntry-cntry.
Append int_fligh.
Endloop.
The above mentioned can be more optimized by using the following code.
Sort int_cntry by cntry.
Delete adjacent duplicates from int_cntry.
If NOT int_cntry[] is INITIAL.
Select * from zfligh appending table int_fligh
For all entries in int_cntry
Where cntry = int_cntry-cntry.
Endif.
Select Statements contd Select Over more than one Internal table
1. Its better to use a views instead of nested Select statements.
2. To read data from several logically connected tables use a join instead of nested Select statements. Joins are preferred only if all the primary key are available in WHERE clause for the tables that are joined. If the primary keys are not provided in join the Joining of tables itself takes time.
3. Instead of using nested Select loops it is often better to use subqueries.
Point # 1
SELECT * FROM DD01L INTO DD01L_WA
WHERE DOMNAME LIKE 'CHAR%'
AND AS4LOCAL = 'A'.
SELECT SINGLE * FROM DD01T INTO DD01T_WA
WHERE DOMNAME = DD01L_WA-DOMNAME
AND AS4LOCAL = 'A'
AND AS4VERS = DD01L_WA-AS4VERS
AND DDLANGUAGE = SY-LANGU.
ENDSELECT.
The above code can be more optimized by extracting all the data from view DD01V_WA
SELECT * FROM DD01V INTO DD01V_WA
WHERE DOMNAME LIKE 'CHAR%'
AND DDLANGUAGE = SY-LANGU.
ENDSELECT
Point # 2
SELECT * FROM EKKO INTO EKKO_WA.
SELECT * FROM EKAN INTO EKAN_WA
WHERE EBELN = EKKO_WA-EBELN.
ENDSELECT.
ENDSELECT.
The above code can be much more optimized by the code written below.
SELECT PF1 PF2 FF3 FF4 INTO TABLE ITAB
FROM EKKO AS P INNER JOIN EKAN AS F
ON PEBELN = FEBELN.
Point # 3
SELECT * FROM SPFLI
INTO TABLE T_SPFLI
WHERE CITYFROM = 'FRANKFURT'
AND CITYTO = 'NEW YORK'.
SELECT * FROM SFLIGHT AS F
INTO SFLIGHT_WA
FOR ALL ENTRIES IN T_SPFLI
WHERE SEATSOCC < F~SEATSMAX
AND CARRID = T_SPFLI-CARRID
AND CONNID = T_SPFLI-CONNID
AND FLDATE BETWEEN '19990101' AND '19990331'.
ENDSELECT.
The above mentioned code can be even more optimized by using subqueries instead of for all entries.
SELECT * FROM SFLIGHT AS F INTO SFLIGHT_WA
WHERE SEATSOCC < F~SEATSMAX
AND EXISTS ( SELECT * FROM SPFLI
WHERE CARRID = F~CARRID
AND CONNID = F~CONNID
AND CITYFROM = 'FRANKFURT'
AND CITYTO = 'NEW YORK' )
AND FLDATE BETWEEN '19990101' AND '19990331'.
ENDSELECT.
1. Table operations should be done using explicit work areas rather than via header lines.
2. Always try to use binary search instead of linear search. But dont forget to sort your internal table before that.
3. A dynamic key access is slower than a static one, since the key specification must be evaluated at runtime.
4. A binary search using secondary index takes considerably less time.
5. LOOP ... WHERE is faster than LOOP/CHECK because LOOP ... WHERE evaluates the specified condition internally.
6. Modifying selected components using MODIFY itab TRANSPORTING f1 f2.. accelerates the task of updating a line of an internal table.
Point # 2
READ TABLE ITAB INTO WA WITH KEY K = 'X BINARY SEARCH.
IS MUCH FASTER THAN USING
READ TABLE ITAB INTO WA WITH KEY K = 'X'.
If TAB has n entries, linear search runs in O( n ) time, whereas binary search takes only O( log2( n ) ).
Point # 3
READ TABLE ITAB INTO WA WITH KEY K = 'X'. IS FASTER THAN USING
READ TABLE ITAB INTO WA WITH KEY (NAME) = 'X'.
Point # 5
LOOP AT ITAB INTO WA WHERE K = 'X'.
ENDLOOP.
The above code is much faster than using
LOOP AT ITAB INTO WA.
CHECK WA-K = 'X'.
ENDLOOP.
Point # 6
WA-DATE = SY-DATUM.
MODIFY ITAB FROM WA INDEX 1 TRANSPORTING DATE.
The above code is more optimized as compared to
WA-DATE = SY-DATUM.
MODIFY ITAB FROM WA INDEX 1.
7. Accessing the table entries directly in a "LOOP ... ASSIGNING ..." accelerates the task of updating a set of lines of an internal table considerably
8. If collect semantics is required, it is always better to use to COLLECT rather than READ BINARY and then ADD.
9. "APPEND LINES OF itab1 TO itab2" accelerates the task of appending a table to another table considerably as compared to LOOP-APPEND-ENDLOOP.
10. DELETE ADJACENT DUPLICATES accelerates the task of deleting duplicate entries considerably as compared to READ-LOOP-DELETE-ENDLOOP.
11. "DELETE itab FROM ... TO ..." accelerates the task of deleting a sequence of lines considerably as compared to DO -DELETE-ENDDO.
Point # 7
Modifying selected components only makes the program faster as compared to Modifying all lines completely.
e.g,
LOOP AT ITAB ASSIGNING <WA>.
I = SY-TABIX MOD 2.
IF I = 0.
<WA>-FLAG = 'X'.
ENDIF.
ENDLOOP.
The above code works faster as compared to
LOOP AT ITAB INTO WA.
I = SY-TABIX MOD 2.
IF I = 0.
WA-FLAG = 'X'.
MODIFY ITAB FROM WA.
ENDIF.
ENDLOOP.
Point # 8
LOOP AT ITAB1 INTO WA1.
READ TABLE ITAB2 INTO WA2 WITH KEY K = WA1-K BINARY SEARCH.
IF SY-SUBRC = 0.
ADD: WA1-VAL1 TO WA2-VAL1,
WA1-VAL2 TO WA2-VAL2.
MODIFY ITAB2 FROM WA2 INDEX SY-TABIX TRANSPORTING VAL1 VAL2.
ELSE.
INSERT WA1 INTO ITAB2 INDEX SY-TABIX.
ENDIF.
ENDLOOP.
The above code uses BINARY SEARCH for collect semantics. READ BINARY runs in O( log2(n) ) time. The above piece of code can be more optimized by
LOOP AT ITAB1 INTO WA.
COLLECT WA INTO ITAB2.
ENDLOOP.
SORT ITAB2 BY K.
COLLECT, however, uses a hash algorithm and is therefore independent
of the number of entries (i.e. O(1)) .
Point # 9
APPEND LINES OF ITAB1 TO ITAB2.
This is more optimized as compared to
LOOP AT ITAB1 INTO WA.
APPEND WA TO ITAB2.
ENDLOOP.
Point # 10
DELETE ADJACENT DUPLICATES FROM ITAB COMPARING K.
This is much more optimized as compared to
READ TABLE ITAB INDEX 1 INTO PREV_LINE.
LOOP AT ITAB FROM 2 INTO WA.
IF WA = PREV_LINE.
DELETE ITAB.
ELSE.
PREV_LINE = WA.
ENDIF.
ENDLOOP.
Point # 11
DELETE ITAB FROM 450 TO 550.
This is much more optimized as compared to
DO 101 TIMES.
DELETE ITAB INDEX 450.
ENDDO.
12. Copying internal tables by using ITAB2[ ] = ITAB1[ ] as compared to LOOP-APPEND-ENDLOOP.
13. Specify the sort key as restrictively as possible to run the program faster.
Point # 12
ITAB2[] = ITAB1[].
This is much more optimized as compared to
REFRESH ITAB2.
LOOP AT ITAB1 INTO WA.
APPEND WA TO ITAB2.
ENDLOOP.
Point # 13
SORT ITAB BY K. makes the program runs faster as compared to SORT ITAB.
Internal Tables contd
Hashed and Sorted tables
1. For single read access hashed tables are more optimized as compared to sorted tables.
2. For partial sequential access sorted tables are more optimized as compared to hashed tables
Hashed And Sorted Tables
Point # 1
Consider the following example where HTAB is a hashed table and STAB is a sorted table
DO 250 TIMES.
N = 4 * SY-INDEX.
READ TABLE HTAB INTO WA WITH TABLE KEY K = N.
IF SY-SUBRC = 0.
ENDIF.
ENDDO.
This runs faster for single read access as compared to the following same code for sorted table
DO 250 TIMES.
N = 4 * SY-INDEX.
READ TABLE STAB INTO WA WITH TABLE KEY K = N.
IF SY-SUBRC = 0.
ENDIF.
ENDDO.
Point # 2
Similarly for Partial Sequential access the STAB runs faster as compared to HTAB
LOOP AT STAB INTO WA WHERE K = SUBKEY.
ENDLOOP.
This runs faster as compared to
LOOP AT HTAB INTO WA WHERE K = SUBKEY.
ENDLOOP. -
Basic query regarding work-area and select query
hi
dear sdn members,
thanks too all for solving all my query's up till now
i am stuck in a problem need help
1) why basically work-area has been used ? the sole purpose
2) different types of select query ? only coding examples
note: no links pls
regards,
virushi,
Work Area
Description for a data object that is particularly useful when working with internal tables or database tables as a source for changing operations or a target for reading operations.
WORKAREA is a structure that can hold only one record at a time. It is a collection of fields. We use workarea as we cannot directly read from a table. In order to interact with a table we need workarea. When a Select Statement is executed on a table then the first record is read and put into the header of the table and from there put into the header or the workarea(of the same structure as that of the table)of the internal table and then transferred top the body of the internal table or directly displayed from the workarea.
Each row in a table is a record and each column is a field.
While adding or retrieving records to / from internal table we have to keep the record temporarily.
The area where this record is kept is called as work area for the internal table. The area must have the same structure as that of internal table. An internal table consists of a body and an optional header line.
Header line is a implicit work area for the internal table. It depends on how the internal table is declared that the itab will have the header line or not.
.g.
data: begin of itab occurs 10,
ab type c,
cd type i,
end of itab. " this table will have the header line.
data: wa_itab like itab. " explicit work area for itab
data: itab1 like itab occurs 10. " table is without header line.
The header line is a field string with the same structure as a row of the body, but it can only hold a single row.
It is a buffer used to hold each record before it is added or each record as it is retrieved from the internal table. It is the default work area for the internal table.
With header line
SELECT.
Put the curson on that word and press F1 . You can see the whole documentation for select statements.
select statements :
SELECT result
FROM source
INTO|APPENDING target
[[FOR ALL ENTRIES IN itab] WHERE sql_cond]
Effect
SELECT is an Open-SQL-statement for reading data from one or several database tables into data objects.
The select statement reads a result set (whose structure is determined in result ) from the database tables specified in source, and assigns the data from the result set to the data objects specified in target. You can restrict the result set using the WHERE addition. The addition GROUP BY compresses several database rows into a single row of the result set. The addition HAVING restricts the compressed rows. The addition ORDER BY sorts the result set.
The data objects specified in target must match the result set result. This means that the result set is either assigned to the data objects in one step, or by row, or by packets of rows. In the second and third case, the SELECT statement opens a loop, which which must be closed using ENDSELECT. For every loop pass, the SELECT-statement assigns a row or a packet of rows to the data objects specified in target. If the last row was assigned or if the result set is empty, then SELECT branches to ENDSELECT . A database cursor is opened implicitly to process a SELECT-loop, and is closed again when the loop is ended. You can end the loop using the statements from section leave loops.
Up to the INTO resp. APPENDING addition, the entries in the SELECTstatement define which data should be read by the database in which form. This requirement is translated in the database interface for the database system´s programming interface and is then passed to the database system. The data are read in packets by the database and are transported to the application server by the database server. On the application server, the data are transferred to the ABAP program´s data objects in accordance with the data specified in the INTO and APPENDING additions.
System Fields
The SELECT statement sets the values of the system fields sy-subrc and sy-dbcnt.
sy-subrc Relevance
0 The SELECT statement sets sy-subrc to 0 for every pass by value to an ABAP data object. The ENDSELECT statement sets sy-subrc to 0 if at least one row was transferred in the SELECT loop.
4 The SELECT statement sets sy-subrc to 4 if the result set is empty, that is, if no data was found in the database.
8 The SELECT statement sets sy-subrc to 8 if the FOR UPDATE addition is used in result, without the primary key being specified fully after WHERE.
After every value that is transferred to an ABAP data object, the SELECT statement sets sy-dbcnt to the number of rows that were transferred. If the result set is empty, sy-dbcnt is set to 0.
Notes
Outside classes, you do not need to specify the target area with INTO or APPENDING if a single database table or a single view is specified statically after FROM, and a table work area dbtab was declared with the TABLES statement for the corresponding database table or view. In this case, the system supplements the SELECT-statement implicitly with the addition INTO dbtab.
Although the WHERE-condition is optional, you should always specify it for performance reasons, and the result set should not be restricted on the application server.
SELECT-loops can be nested. For performance reasons, you should check whether a join or a sub-query would be more effective.
Within a SELECT-loop you cannot execute any statements that lead to a database commit and consequently cause the corresponding database cursor to close.
SELECT - result
Syntax
... lines columns ... .
Effect
The data in result defines whether the resulting set consists of multiple rows (table-like structure) or a single row ( flat structure). It specifies the columns to be read and defines their names in the resulting set. Note that column names from the database table can be changed. For single columns, aggregate expressions can be used to specify aggregates. Identical rows in the resulting set can be excluded, and individual rows can be protected from parallel changes by another program.
The data in result consists of data for the rows lines and for the columns columns.
SELECT - lines
Syntax
... { SINGLE }
| { { } } ... .
Alternatives:
1. ... SINGLE
2. ... { }
Effect
The data in lines specifies that the resulting set has either multiple lines or a single line.
Alternative 1
... SINGLE
Effect
If SINGLE is specified, the resulting set has a single line. If the remaining additions to the SELECT command select more than one line from the database, the first line that is found is entered into the resulting set. The data objects specified after INTO may not be internal tables, and the APPENDING addition may not be used.
An exclusive lock can be set for this line using the FOR UPDATE addition when a single line is being read with SINGLE. The SELECT command is used in this case only if all primary key fields in logical expressions linked by AND are checked to make sure they are the same in the WHERE condition. Otherwise, the resulting set is empty and sy-subrc is set to 8. If the lock causes a deadlock, an exception occurs. If the FOR UPDATE addition is used, the SELECT command circumvents SAP buffering.
Note
When SINGLE is being specified, the lines to be read should be clearly specified in the WHERE condition, for the sake of efficiency. When the data is read from a database table, the system does this by specifying comparison values for the primary key.
Alternative 2
Effect
If SINGLE is not specified and if columns does not contain only aggregate expressions, the resulting set has multiple lines. All database lines that are selected by the remaining additions of the SELECT command are included in the resulting list. If the ORDER BY addition is not used, the order of the lines in the resulting list is not defined and, if the same SELECT command is executed multiple times, the order may be different each time. A data object specified after INTO can be an internal table and the APPENDING addition can be used. If no internal table is specified after INTO or APPENDING, the SELECT command triggers a loop that has to be closed using ENDSELECT.
If multiple lines are read without SINGLE, the DISTINCT addition can be used to exclude duplicate lines from the resulting list. If DISTINCT is used, the SELECT command circumvents SAP buffering. DISTINCT cannot be used in the following situations:
If a column specified in columns has the type STRING, RAWSTRING, LCHAR or LRAW
If the system tries to access pool or cluster tables and single columns are specified in columns.
Note
When specifying DISTINCT, note that you have to carry out sort operations in the database system for this.
SELECT - columns
Syntax
| { {col1|aggregate( col1 )}
{col2|aggregate( col2 )} ... }
| (column_syntax) ... .
Alternatives:
1. ... *
2. ... {col1|aggregate( col1 )}
{col2|aggregate( col2 )} ...
3. ... (column_syntax)
Effect
The input in columns determines which columns are used to build the resulting set.
Alternative 1
Effect
If * is specified, the resulting set is built based on all columns in the database tables or views specified after FROM, in the order given there. The columns in the resulting set take on the name and data type from the database tables or views. Only one data object can be specified after INTO.
Note
If multiple database tables are specified after FROM, you cannot prevent multiple columns from getting the same name when you specify *.
Alternative 2
... {col1|aggregate( col1 )}
{col2|aggregate( col2 )} ...
Effect
A list of column labels col1 col2 ... is specified in order to build the resulting list from individual columns. An individual column can be specified directly or as an argument of an aggregate function aggregate. The order in which the column labels are specified is up to you and defines the order of the columns in the resulting list. Only if a column of the type LCHAR or LRAW is listed does the corresponding length field also have to be specified directly before it. An individual column can be specified multiple times.
The addition AS can be used to define an alternative column name a1 a2 ... with a maximum of fourteen digits in the resulting set for every column label col1 col2 .... The system uses the alternative column name in the additions INTO|APPENDING CORRESPONDING FIELDS and ORDER BY. .
Column labels
The following column labels are possible:
If only a single database table or a single view is specified after FROM, the column labels in the database table - that is, the names of the components comp1 comp2... - can be specified directly for col1 col2 ... in the structure of the ABAP Dictionary.
If the name of the component occurs in multiple database tables of the FROM addition, but the desired database table or the view dbtab is only specified once after FROM, the names dbtab~comp1 dbtab~comp2 ... have to be specified for col1 col2 .... comp1 comp2 ... are the names of the components in the structure of the ABAP Dictionary.
If the desired database table or view occurs multiple times after FROM, the names tabalias~comp1 tabalias~comp2 ... have to be specified for col1 col2 .... tabalias is the alternative table name of the database table or view defined after FROM, and comp1 comp2 ... are the names of the components in the structure of the ABAP Dictionary.
The data type of a single column in the resulting list is the datatype of the corresponding component in the ABAP Dictionary. The corresponding data object after INTO or APPENDING has to be selected accordingly.
Note
If multiple database tables are specified after FROM, you can use alternative names when specifying single columns to avoid having multiple columns with the same name.
Example
Read specific columns of a single row.
DATA wa TYPE spfli.
SELECT SINGLE carrid connid cityfrom cityto
INTO CORRESPONDING FIELDS OF wa
FROM spfli
WHERE carrid EQ 'LH' AND connid EQ '0400'.
IF sy-subrc EQ 0.
WRITE: / wa-carrid, wa-connid, wa-cityfrom, wa-cityto.
ENDIF.
Alternative 3
... (column_syntax)
Effect
Instead of static data, a data object column_syntax in brackets can be specified, which, when the command is executed, either contains the syntax shown with the static data, or is initial. The data object column_syntax can be a character-type data object or an internal table with a character-type data type. The syntax in column_syntax, like in the ABAP editor, is not case-sensitive. When specifying an internal table, you can distribute the syntax over multiple rows.
If column_syntax is initial when the command is executed, columns is implicitly set to * and all columns are read.
If columns are specificied dynamically without the SINGLE addition, the resulting set is always regarded as having multiple rows.
Notes
Before Release 6.10, you could only specify an internal table with a flat character-type row type for column_syntax with a maximum of 72 characters. Also, before Release 6.10, if you used the DISTINCT addition for dynamic access to pool tables or cluster tables, this was ignored, but since release 6.10, this causes a known exception.
If column_syntax is an internal table with header line, the table body and not the header line is evaluated.
Example
Read out how many flights go to and from a city. The SELECT command is implemented only once in a sub-program. The column data, including aggregate function and the data after GROUP BY, is dynamic. Instead of adding the column data to an internal l_columns table, you could just as easily concatenate it in a character-type l_columns field.
PERFORM my_select USING `CITYFROM`.
ULINE.
PERFORM my_select USING `CITYTO`.
FORM my_select USING l_group TYPE string.
DATA: l_columns TYPE TABLE OF string,
l_container TYPE string,
l_count TYPE i.
APPEND l_group TO l_columns.
APPEND `count( * )` TO l_columns.
SELECT (l_columns)
FROM spfli
INTO (l_container, l_count)
GROUP BY (l_group).
WRITE: / l_count, l_container.
ENDSELECT.
ENDFORM.
SELECT - aggregate
Syntax
... { MAX( col )
| MIN( col )
| AVG( col )
| SUM( col )
| COUNT( DISTINCT col )
| COUNT( * )
| count(*) } ... .
Effect
As many of the specified column labels as you like can be listed in the SELECT command as arguments of the above aggregate expression. In aggregate expressions, a single value is calculated from the values of multiple rows in a column as follows (note that the addition DISTINCT excludes double values from the calculation):
MAX( col ) Determines the maximum value of the value in the column col in the resulting set or in the current group.
MIN( col ) Determines the minimum value of the content of the column col in the resulting set or in the current group.
AVG( col ) Determines the average value of the content of the column col in the resulting set or in the current group. The data type of the column has to be numerical.
SUM( col ) Determines the sum of the content of the column col in the resulting set or in the current group. The data type of the column has to be numerical.
COUNT( DISTINCT col ) Determines the number of different values in the column col in the resulting set or in the current group.
COUNT( * ) (or count(*)) Determines the number of rows in the resulting set or in the current group. No column label is specified in this case.
If you are using aggregate expressions, all column labels that are not listed as an argument of an aggregate function are listed after the addition GROUP BY. The aggregate functions evaluate the content of the groups defined by GROUP BY in the database system and transfer the result to the combined rows of the resulting set.
The data type of aggregate expressions with the function MAX, MIN or SUM is the data type of the corresponding column in the ABAP Dictionary. Aggregate expressions with the function AVG have the data type FLTP, and those with COUNT have the data type INT4. The corresponding data object after INTO or APPENDING has to be selected accordingly.
Note the following points when using aggregate expressions:
If the addition FOR ALL ENTRIES is used in front of WHERE, or if cluster or pool tables are listed after FROM, no other aggregate expressions apart from COUNT( * ) can be used.
Columns of the type STRING or RAWSTRING cannot be used with aggregate functions.
When aggregate expressions are used, the SELECT command makes it unnecessary to use SAP buffering.
Null values are not included in the calculation for the aggregate functions. The result is a null value only if all the rows in the column in question contain the null value.
If only aggregate expressions are used after SELECT, the results set has one row and the addition GROUP BY is not necessary. If a non-table type target area is specified after INTO, the command ENDSELECT cannot be used together with the addition SINGLE. If the aggregate expression count( * ) is not being used, an internal table can be specified after INTO, and the first row of this table is filled.
If aggregate functions are used without GROUP BY being specified at the same time, the resulting set also contains a row if no data is found in the database. If count( * ) is used, the column in question contains the value 0. The columns in the other aggregate functions contain initial values. This row is assigned to the data object specified after INTO, and unless count( * ) is being used exclusively, sy-subrc is set to 0 and sy-dbcnt is set to 1. If count( *) is used exclusively, the addition INTO can be omitted and if no data can be found in the database, sy-subrc is set to 4 and sy-dbcnt is set to 0.
if helpful reward points -
Concatenate name in select query...
Hi Pals,
I was wondering how to directly concetenate client name in the select query itself...
Currently the code says :
SELECT SINGLE NAME1 NAME2
INTO (V_NAME1,V_NAME2)
FROM KNA1
WHERE KUNNR = I_PROJ-ZZCLIENT.
CONCATENATE V_NAME1 V_NAME2 INTO I_PROJ-CLNAME SEPARATED BY SPACE.
Can we say some thing like...
SELECT SINGLE ( NAME1 + ' ' + NAME2 ) AS CLNAME
INTO I_PROJ-CLNAME
FROM KNA1
WHERE KUNNR = I_PROJ-ZZCLIENT.
But its giving error...
Basically i need a single select query which would give me space seperated clientname in I_PROJ directly
Please help me...
Regards,
Abhishek B.Hi Abhishek,
OPEN SQL.
1. Sap works on the concept of Open Sql.
ie. Sql is database independent.
2. ABAP Syntax does not have provision for
using such EXPRESSIONS (like concatenate)
directly in SQL.
3. However u may use them in Native Sql.
4. In open sql one can use aggregate functions
like SUM COUNT etc.
But Concatenate is not allowed.
Hope u find the answer useful.
(To newbees)
U may please award points (if u find the reply useful)
by clicking on the STAR on the left of the reply.
Regards,
Amit M. -
Hi,
I'm in Oracle 11g, need some help writing aggregate sql select. That might be really easy I hope.
We are doing some web analytics and counting clicks on a company’s web site, so I have to count sums on clicks, visitors and sessions from activity table.
t_agg_activity( date_key, site_id, segment_id, page_id, visitor_count, views_count, session_count)
The problem is with the Totals numbers. There are visitors and their segments. Segments are also divided by groups. So I need to count records and distinct visitors and distinct sessions.
Also I need three records for Totals: total all and total in group 1 and total in group 2 with the segment key -1, -2, -3 respectively. No Totals for group 3 needed.
Not sure how to deal with those totals. Should I use Roll Up function or analytic SUM function may be?
create table t_sites(site_id NUMBER, site_code VARCHAR2(50));
insert into t_sites(site_id , site_code )
values( 1, 'site_1');
insert into t_sites(site_id , site_code )
values( 2, 'site_2');
insert into t_sites(site_id , site_code )
values( 3, 'site_3');
create table t_segments(segment_id NUMBER, segment_group VARCHAR2(50), segment_code VARCHAR2(50));
insert into t_segments(segment_id , segment_group , segment_code )
values(1, 'seg_group_1', 'AAA');
insert into t_segments(segment_id , segment_group , segment_code )
values(2, 'seg_group_1', 'BBB');
insert into t_segments(segment_id , segment_group , segment_code )
values(3, 'seg_group_1', 'CCC');
insert into t_segments(segment_id , segment_group , segment_code )
values(4, 'seg_group_2', 'DDD');
insert into t_segments(segment_id , segment_group , segment_code )
values(5, 'seg_group_2', 'EEE');
insert into t_segments(segment_id , segment_group , segment_code )
values(6, 'seg_group_2', 'FFF');
insert into t_segments(segment_id , segment_group , segment_code )
values(7, 'seg_group_3', 'GGG');
insert into t_segments(segment_id , segment_group , segment_code )
values(8, 'seg_group_3', 'HHH');
insert into t_segments(segment_id , segment_group , segment_code )
values(9, 'seg_group_3', 'III');
insert into t_segments(segment_id , segment_group , segment_code )
values(-1, 'Total All', 'Total');
insert into t_segments(segment_id , segment_group , segment_code )
values(-2, 'Total seg_group_1', 'Total G1');
insert into t_segments(segment_id , segment_group , segment_code )
values(-3, 'Total seg_group_2', 'Total G2');
create table t_activity( date_key NUMBER, page_id NUMBER, site_id NUMBER, segment_id NUMBER, visitor_id NUMBER, session_id NUMBER);
insert into t_activity( date_key, page_id, site_id, segment_id, visitor_id, session_id)
values( 2456141, 1, 1, 1, 1, 1);
insert into t_activity( date_key, page_id,site_id, segment_id, visitor_id, session_id)
values( 2456141, 1, 1, 1, 1, 1);
insert into t_activity( date_key, page_id,site_id, segment_id, visitor_id, session_id)
values( 2456141, 1, 1, 1, 1, 2);
insert into t_activity( date_key, page_id,site_id, segment_id, visitor_id, session_id)
values( 2456141, 1, 1, 1, 2, 2);
insert into t_activity( date_key, page_id,site_id, segment_id, visitor_id, session_id)
values( 2456141, 1, 1, 1, 2, 2);
insert into t_activity( date_key, page_id,site_id, segment_id, visitor_id, session_id)
values( 2456141, 1, 1, 1, 2, 22);
insert into t_activity( date_key, page_id,site_id, segment_id, visitor_id, session_id)
values( 2456141, 1, 1, 4, 2, 10);
insert into t_activity( date_key, page_id,site_id, segment_id, visitor_id, session_id)
values( 2456141, 1, 1, 4, 2, 10);
insert into t_activity( date_key, page_id,site_id, segment_id, visitor_id, session_id)
values( 2456141, 1, 1, 4, 2, 10);
insert into t_activity( date_key, page_id,site_id, segment_id, visitor_id, session_id)
values( 2456141, 1, 1, 7, 3, 100);
insert into t_activity( date_key, page_id,site_id, segment_id, visitor_id, session_id)
values( 2456141, 1, 1, 7, 3, 100);
insert into t_activity( date_key, page_id,site_id, segment_id, visitor_id, session_id)
values( 2456141, 1, 1, 7, 3, 100);
create table t_agg_activity( date_key NUMBER, site_id NUMBER, segment_id NUMBER, page_id NUMBER, visitor_count NUMBER, views_count NUMBER, session_count NUMBER)
Edited by: 955537 on Aug 28, 2012 11:19 AM955537 wrote:
If you can help with the full query?
with t as (
select nvl2(segment_group,'Total ' || segment_group,'Total All') segment_group,
count(*) cnt
from t_activity a,
t_segments s
where s.segment_id = a.segment_id
group by rollup(segment_group)
select segment_id,
count(*)
from t_activity
group by segment_id
union all
select segment_id,
cnt
from t,
t_segments s
where s.segment_group = t.segment_group
SEGMENT_ID COUNT(*)
1 6
4 3
7 3
-1 12
-2 6
-3 3
6 rows selected.
SQL> SY. -
Hi,
When I try to do select query on MDO objects, I could see there are many restriction in executing the SELECT statement unlike doing with traditional database.
For example, I am not able to use any of the aggregate function (like sum, count, average) and other select function like SELECT SINGLE, SELECT DISTINCT,,, etc.
I know we could accomplish the above function by getting the data into BLT. But is there is any other way we could execute MDO query directly for this functions?
Thanks
MaheshYes Mahesh,
We cant add any SQL functions in the select statements in an MDO.
But if you want to still use them, there is an alternative though not an easy one.
You can connect the MDO instance in your SQL DB and then access the MDO object as a SQL table. Here you can apply all the SQL functions to your MDO object and you can even use them in your fixed query.
Disadvantages:
1.The MDO created in the DB will not be the same name as in your Workbench but rather a system defined.
2. The field names will not be the same as that defined in MDO, but rather field1,field2 and so on... So you need to work with the sequence rather than the names.
As i said a bit painful but can be used in case you dont have a workaround. I hope it helps.
Regards,
Satpreet Singh -
Questions on the most efficient select query..
What is the difference between the two select query & please explain y is the 2nd select query more efficient??
DATA: MAX_MSGNR type t100-msgnr.
MAX_MSGNR = '000'.
SELECT * FROM T100 INTO T100_WA
WHERE SPRSL = 'D' AND
ARBGB = '00'.
CHECK: T100_WA-MSGNR > MAX_MSGNR.
MAX_MSGNR = T100_WA-MSGNR.
ENDSELECT.
DATA: MAX_MSGNR type t100-msgnr.
SELECT MAX( MSGNR ) FROM T100 INTO max_msgnr
WHERE SPRSL = 'D' AND
ARBGB = '00'.Hi,
First never use Check statement in the Select.
Next thing Select ... end select.
Coming to ur question In case of first select it will fetch each record from the data base and compares that record value with the variable(MAX_MSGNR) and assigns the value to the variable. And this process will continue till the select reads all the records of the data base. Also these operations happens on the data base server. SO this query not only affect ur program but also others who is accessing the same data base.
Second query is most efficient because of the aggregate function MAX. Here it will fetch all the records in single go and checks the max value for that column using
optimising algorithm. So number of checks, assignments(single assignment) and fetches will be less compared to first select. This is the main reason. Hope this clarified ur doubt.
Another thing is in first query we are selecting all the fields where as in second we are selecting only one field(required)
Thanks,
Vinod.
Edited by: Vinod Kumar Vemuru on Mar 13, 2008 4:55 PM -
Aggregate Hit by query are not shouwing up
Hello Friends. i am facing issue with aggregate not being hit. I created the aggregate by using first the field and filter that exist when i run the RSRT with Aggregate found selection . then i use the same list of fields and created the aggregate. now when i am running the RSRT and choose display aggregate found it still display the cube name in Column Cube/Aggregate.
also checked sto3n it shows the aggregate but say 0 execution
1. i did activated and filled the aggregated
2. i did check its all green
How do i make 100% sure that my aggregate is not being hit by report. if thats the case then how do i fix it so that query hit the aggregate. even though i am putting the same selection like month march 2008 as fiscal year period.
i did not see the fiscal year variant field in aggregate but i see that comes with fiscal year / period
please help resolve the issue
Thanks
Regards
Soniyahi,
Any updates... -
Hi Experts,
I am having a select query in which I am using a variable in the where condition but it is giving error. Please suggest how to use variable in the select query.
The query I am using is a s below.
select * from zexc_rec into table it_ZEXC_REC
where
LIFNR in S_LIFNR and
DOCNO in S_DOCNO and
DOCTYP in doc_typ and
DATE1 in S_DATE1 and
MATNR in S_MATNR.
Here doc_typ is a variable.
Thanks.Rahul,
use RANGES type variable instead of variable . It acts as a select-options variable. Thn use this variable in SELECT query with IN.
Eg :
RANGES r_t510 FOR t510-lgart.
r_t510-low = '1600'.
APPEND r_t510.
r_t510-low = '3190'.
APPEND r_t510.
Note : can be use SIGN, OPTIONS properties too in RANGES type.
More deatils go through on HELP of RANGES
Rgds,
Ranjith -
Oracle 11g :SELECT query blocked..??
Hi Experts,
could you please explain why the below SQL query is blocked?
SELECT 1 FROM DUAL is blocking the SQL statement on GTTAPPUSR@gttccuatcriba04 ( SID=469 ) blocked SQL -> DELETE FROM GTTDB.PURCHASE_ENTRY_ID=:1
SELECT 1 FROM DUAL is blocking the SQL statement on GTTAPPUSR@gttccuatcriba04 ( SID=367 ) blocked SQL -> DELETE FROM GTTDB.PURCHASE_ENTRY_ID=:1
I am scratching my head without any solution when I had a look at the db today. Thanks in advance for your help.
Regards,
Boris
Edited by: user12075620 on Dec 4, 2012 8:58 AMThe SELECT statement is not blocking the UPDATE. As I said in the previous reply, the string that this query produces does not match the logic.
This query is (at least on the surface) correctly identifying that session 1 is blocking session 2. Session 1 holds some lock that session 2 is waiting on. So far, so good. Since session 2 is waiting on the lock, we can easily enough see what session 2 is running (the UPDATE statement). But since session 1 is not blocked, it is potentially off running a ton of other SQL statements (or no SQL statement at all). The query is looking to see what session 1 is running currently. It has no way of determining what session 1 ran at some point in the past to acquire the lock in the first place.
Going back to my KING example,
At noon, session 1 runs
UPDATE emp
SET sal = sal * 2
WHERE ename = 'KING'Session 1 now has a lock on the KING row in the EMP table. But session 1 neither commits nor rolls back, it is still in a transaction. Session 1 might not have any more activity for a long time-- the user might go off to lunch, for example (obviously, applications should not be designed to allow users to maintain open transactions indefinitely, but not all applications are designed correctly). Or it might start running other queries. Let's say that session 1 now runs a query that is going to go for an hour
SELECT *
FROM giant_view_with_lots_of_computationsNow, at 12:45, session 2 comes in and runs
UPDATE emp
SET bonus = 100
WHERE ename = 'KING'Session 2 is blocked. Session 2 is running the UPDATE statement. Session 1 still holds the lock but it is running some completely unrelated SQL statement.
If we run the query you posted, the query will correctly report that session 1 is running the query against the GIANT_VIEW_WITH_LOTS_OF_COMPUTATIONS but incorrectly imply that this SELECT query is the source of the lock. It is not. It simply happens to be the query that the session that does hold the lock happens to be executing at the current moment (why the application seems to be running a lot of queries that select a constant from dual is a separate question).
Justin -
Oracle SQL Select query takes long time than expected.
Hi,
I am facing a problem in SQL select query statement. There is a long time taken in select query from the Database.
The query is as follows.
select /*+rule */ f1.id,f1.fdn,p1.attr_name,p1.attr_value from fdnmappingtable f1,parametertable p1 where p1.id = f1.id and ((f1.object_type ='ne_sub_type.780' )) and ( (f1.id in(select id from fdnmappingtable where fdn like '0=#1#/14=#S0058-3#/17=#S0058-3#/18=#1#/780=#5#%')))order by f1.id asc
This query is taking more than 4 seconds to get the results in a system where the DB is running for more than 1 month.
The same query is taking very few milliseconds (50-100ms) in a system where the DB is freshly installed and the data in the tables are same in both the systems.
Kindly advice what is going wrong??
Regards,
PurushothamSQL> @/alcatel/omc1/data/query.sql
2 ;
9 rows selected.
Execution Plan
Plan hash value: 3745571015
| Id | Operation | Name |
| 0 | SELECT STATEMENT | |
| 1 | SORT ORDER BY | |
| 2 | NESTED LOOPS | |
| 3 | NESTED LOOPS | |
| 4 | TABLE ACCESS FULL | PARAMETERTABLE |
|* 5 | TABLE ACCESS BY INDEX ROWID| FDNMAPPINGTABLE |
|* 6 | INDEX UNIQUE SCAN | PRIMARY_KY_FDNMAPPINGTABLE |
|* 7 | TABLE ACCESS BY INDEX ROWID | FDNMAPPINGTABLE |
|* 8 | INDEX UNIQUE SCAN | PRIMARY_KY_FDNMAPPINGTABLE |
Predicate Information (identified by operation id):
5 - filter("F1"."OBJECT_TYPE"='ne_sub_type.780')
6 - access("P1"."ID"="F1"."ID")
7 - filter("FDN" LIKE '0=#1#/14=#S0058-3#/17=#S0058-3#/18=#1#/780=#5#
8 - access("F1"."ID"="ID")
Note
- rule based optimizer used (consider using cbo)
Statistics
0 recursive calls
0 db block gets
0 consistent gets
0 physical reads
0 redo size
0 bytes sent via SQL*Net to client
0 bytes received via SQL*Net from client
0 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
9 rows processed
SQL> -
Select query differences between oracle 9 and oracle 8.
Hi,
I have a problem using the select query between oracle 7 and oracle 9i I don't have the same result :
ex:
With oracle7
SQL> select 'champ1','champ2' from DUAL;
'CHAMP 'CHAMP
champ1 champ2
With Oracle 9
SQL> select 'champ1','champ2' from DUAL;
'CHAMP1' 'CHAMP2'
champ1 champ2
So Can someone tell me how to solve this problem ? Is there a parameter in oracle 9 to set?
Thanx.Whenever you are posting anything over internet forums like this - you should be very careful about not just posting the details which requires to solve the problem - also should be sensible about your question.
This is not at all desired when you are posting such question. It may be because - you may not well aware of the fact.
My suggestion is -> First Go through the basics Of SQL in general.
Then go for any specific product like Oracle/ SQL Server/ Sybase etc.
And, finally learn the advanced commands of that DB.
You asked it - may be you thought the difference in output in terms of lines. But, that is not your actual output. That is the graphical display part only.
Anyway,
You can get the quite familier output by first type the following command ->
set lin 310Regards.
Satyaki De.
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