Slow performance of Query-Large Table how to optimize for performance
Hi Friends,
I am an ORacle DBA and just recently I have been asked to Administer an ORacle HRMS Database as a substitute for the HRMS DBA who have gone on vacation.
I have been reported that few queries are taking a long time to refresh and populate the forms. After some investigation it is found that the tables: HR.PAY_ELEMENT_ENTRY_VALUES_F has some more than 15 million rows in it. The storage parameters specified for table r Oracle Defaults. The table has grown a lot big and even a Count(*) takes more than 7 mins to respond.
My question is: Is there anyway it can be tuned for better performance without an overhaul. Is it normal for this table to grow this big for 6000 employees data for 4 years....
Any response/help in this regard will be appreciated. U may please ans me at [email protected]
Thanks in Advance.
Rajeev.
That was a good suggestion by Karthick_Arp, but there is a chance that it is not logically identical depending on the data (I believe that is the reason for his warning).
Try this rewrite, which moves T6 to an inline view and uses the DECODE function to determine if the one row returned from T6 should be used:
SELECT
ASSOC.NAME_FIRST || ' ' || ASSOC.NAME_LAST AS CLIENT_MANAGER
FROM
T1 ASSOC,
T2 CE,
T3 AA,
T4 ACT,
T5 CC,
(SELECT
CA.ASSOC_ID
FROM
T6 CA
WHERE
CA.COMP_ID = :P_ENT_ID
AND CA.CD_CODE IN ('CMG','RCM','BCM','CCM','BAE')
GROUP BY
CA.ASSOC_ID) CA
WHERE
CE.ENT_ID = ACT.PRIMARY_ENT_ID(+)
AND CE.ENT_ID = :P_ENT_ID
AND ASSOC.ID = DECODE(AA.ASSOC_ID, NULL, CA.ASSOC_ID, AA.ASSOC_ID)
AND NVL(ACT.ACTIVITY_ID, 0) = NVL(AA.ACTIVITY_ID, 0)
AND ASSOC.BK_CODE = CC.CPY_NO
AND ASSOC.CENTER = CC.CCT_NO
AND AA.ROLE_CODE IN ('CMG', 'RCM', 'BCM', 'CCM', 'BAE');Charles Hooper
IT Manager/Oracle DBA
K&M Machine-Fabricating, Inc.
Similar Messages
-
Efficiently Querying Large Table
I have to query a recordset of 14k records against (join) a very large table: billions of data -even a count of the table does not return any resulty after 15 mins.
I tried a plsql procedure to store the first recordset in a temp table and then preparing two cursors: one on the temp table and the other on the large table.
However, the plsql procedure runs for a long time and just gives up with this error:
SQL> exec match;
ERROR:
ORA-01041: internal error. hostdef extension doesn't exist
BEGIN match; END;
ERROR at line 1:
ORA-03113: end-of-file on communication channel
Is there is way through which I can query more efficiently?
- Using chucks of records from the large table at a time - how to do that? (rowid)
- Or just ask the dba to partition the table - but the whole table would still need to be queried.
The temp table is:
CREATE TABLE test AS SELECT a.mon_ord_no, a.mo_type_id, a.p2a_pbu_id, a.creation_date,b.status_date_time,
a.expiry_date, a.current_mo_status_desc_id, a.amount,
a.purchaser_name, a.recipent_name, a.mo_id_type_id,
a.mo_redeemed_by_id, a.recipient_type, c.pbu_id, c.txn_seq_no, c.txn_date_time
FROM mon_order a, mo_status b, host_txn_log c
where a.mon_ord_no = b.mon_ord_no
and a.mon_ord_no = c.mon_ord_no
and b.status_date_time = c.txn_date_time
and b.status_desc_id = 7
and a.current_mo_status_desc_id = 7
and a.amount is not null
and a.amount > 0
order by b.status_date_time;
and the PL/SQL Procedure is:
CREATE OR REPLACE PROCEDURE MATCH
IS
--DECLARE
deleted INTEGER :=0;
counter INTEGER :=0;
CURSOR v_table IS
SELECT DISTINCT pbu_id, txn_seq_no, create_date
FROM host_v
WHERE status = 4;
v_table_record v_table%ROWTYPE;
CURSOR temp_table (v_pbu_id NUMBER, v_txn_seq_no NUMBER, v_create_date DATE) IS
SELECT * FROM test
WHERE pbu_id = v_pbu_id
AND txn_seq_no = v_txn_seq_no
AND creation_date = v_create_date;
temp_table_record temp_table%ROWTYPE;
BEGIN
OPEN v_table;
LOOP
FETCH v_table INTO voucher_table_record;
EXIT WHEN v_table%NOTFOUND;
OPEN temp_table (v_table_record.pbu_id, v_table_record.txn_seq_no, v_table_record.create_date);
LOOP
FETCH temp_table INTO temp_table_record;
EXIT WHEN temp_table %FOUND;
DELETE FROM test WHERE pbu_id = v_table_record.pbu_id AND
temp_table_record.txn_seq_no = v_table_record.txn_seq_no AND
temp_table_record.creation_date = v_table_record.create_date;
END LOOP;
CLOSE temp_table;
END LOOP;
CLOSE v_table;
END MATCH;
/Many thanks,
I can get the explain plan for the SQL statement, but I am not sure how to get it for teh PLSQL. Which section in the PLSQL do I get the explain plan. I am using SQL Navigator.
I can create the cursor with the join, and if it does not need the delete statement, then there is no need requirement for the procedure itself. Should I just run the query as a SQL statement?
You have not said what I should do with the rowid?
Regards -
Query a table according to SYSTIMESTAMP for records within an interval
Hello ,
I am trying to query a table based on the systimestamp and taking two timestamp as intervals.Following is the query:
select * FROM MY_TBL where to_char(SYSTIMESTAMP,'YYYY-MM-DD HH24:MI:SS')
BETWEEN (to_char(SYSTIMESTAMP - INTERVAL '40' hour, 'yyyy-mm-dd HH24:MI:SS'))
AND (to_char(SYSTIMESTAMP - INTERVAL '16' hour, 'yyyy-mm-dd HH24:MI:SS'));
I am not getting any results.(no rows selected)
So i tried:
SELECT * FROM MY_TBL AS OF TIMESTAMP
to_date(to_char(SYSTIMESTAMP - INTERVAL '40' hour, 'yyyy-mm-dd HH24:MI:SS'),'YYYY-MM-DD HH24:MI:SS')
- to_date(to_char(SYSTIMESTAMP - INTERVAL '16' hour, 'yyyy-mm-dd HH24:MI:SS'),'YYYY-MM-DD HH24:MI:SS');
ERROR at line 3:
ORA-00932: inconsistent datatypes: expected TIMESTAMP got DATE JULIAN
Since TIMESTAMP is in a different format.I may be getting this error.How do i cast TIMESTAMP in the above query to map to the intervals.
Please let me know how to approach this issue.
Thanks in Advance,
SantoshThanks for the quick and prompt replies....
To provide a quick background.I am providing a daily report to my customer which is based on column (DATE type) in the table.But the records were inconsistent.Hence it was agreed that we get the report based on systime stamp.
Range is : between day-before-yesterday midnight(START_TIME) and yesterday midnight(END_TIME).A perl script runs the report at midnight 2 AM as cron .So i figure the interval can be :
(SYSTIMESTAMP - INTERVAL '40' hour) - It is 12 AM day before-yesterday-night if run at 2 AM - Interval 1
--------------------------------------------------------BETWEEN----------------------------------------------------------------------------
(SYSTIMESTAMP - INTERVAL '16' hour) - It is 12 AM day yesterday-night if run at 2 AM - Interval 2
SQL> select to_timestamp(to_char(SYSTIMESTAMP - INTERVAL '40' hour, 'yyyy-mm-dd HH24:MI:SS'),'YYYY-MM-DD HH24:MI:SS')START_TIME from dual;
START_TIME
08-JUN-09 06.43.59.000000000 PM
SQL> select to_timestamp(to_char(SYSTIMESTAMP - INTERVAL '16' hour, 'yyyy-mm-dd HH24:MI:SS'),'YYYY-MM-DD HH24:MI:SS') END_TIME from dual
2 ;
END_TIME
09-JUN-09 06.44.46.000000000 PM
How do i get the records for these two intervals.
Thankyou..
-Santosh -
VBA needs to pull from multiple tables, how to code for best efficiency?
I have one main table, and three other tables that exist in a one to many relationship off of the main table.
I need data from all 3 tables for my calculation. I'll iteratively run through the recordsets of each of these tables for the record on the main table, to perform my calculation.
Now I need to run this calculation for each record on the main table. I see two options:
1. Query the three tables for relevant records, for each individual record on the master table. I suspect this approach would be computationally inefficient.
2. Create additional logic within my calculation to limit the recordset movement to just the record at hand. I can no longer use end of field, or move first type properties/methods, so this will add a good bit of complexity to already complex code.
I'll need to run this monthly for approx 3000-5000 records.Since you can't include multiple independent 1-many relationships in a single query, I only see two choices.
You can open a recordset for each of the four tables sorted by the main table's primary key. Use an outer loop to move through the main table row by row. Within that loop you loop on each of the child tables using the condition While child.Fields("FK")
= parent.Fields("PK").
Another approach is to define a querydef for each of the child tables including a parameter for the foreign key value. Then within the outer loop you assign the parameter and open a recordset from each of the child querydefs. You're still querying the
database 3 times for each iteration of the parent table, but I think it saves some time to be able to reuse the querydef instead of creating a new one each time.
I think either approach should be fast enough for 3-5,000 records done monthly.
Paul -
ROWNUM is indexed in the Fact table - How to optimize performace with this?
Hi,
I have a scenario where there is an index on the Rownum.
The main Fact table is partitioned based on the job number (Daily and monthly). As there can be multiple entries for a single jobID, the primary key is made up of the Job ID and the Rownum
This fact table in turn is joined with another fact table based on this job number and rownum. This second fact table is also partitioned on job ID.
I have few reference tables that are joined with the first fact table with btree index.
Though in a normal DW scenario we should use bitmap, here we can't do that as lot of other applications are accessing data (DML queries) where bitmap will be slow. So I am using STAR_TRANSFORMATION hint to use the normal index as bitmap index.
Till here it is fine. Problem is when I simply do a count for a specific partition from a reference table and a fact table, it is using all required indexes as bitmap with very low cost. But also it is using ROWNUM index that is of very very high cost.
I am relatively new to Oracle tuning. I am not able to understand what it is exactly doing. Could you please suggest if I can get rid of this ROWNUM to make my query performance faster? This index can not be dropped. Is there a way in the hint I can instruct not to use this primary key index?
Or Even by using is there a way that the performance will be faster?
I will highly appreciate any help in this regard.
Regards
...Just sending the portion having info on the partition and Primary index as the entire script is too big.
CREATE TABLE FACT_TABLE
JOBID VARCHAR2(10 BYTE) DEFAULT '00000000' NOT NULL,
RECID VARCHAR2(18 BYTE) DEFAULT '000000000000000000' NOT NULL,
REP_DATE VARCHAR2(8 BYTE) DEFAULT '00000000' NOT NULL,
LOCATION VARCHAR2(4 BYTE) DEFAULT ' ' NOT NULL,
FUNCTION VARCHAR2(6 BYTE) DEFAULT ' ' NOT NULL,
AMT.....................................................................................
TABLESPACE PSAPPOD
PCTUSED 0
PCTFREE 10
INITRANS 11
MAXTRANS 255
STORAGE (
INITIAL 32248K
LOGGING
PARTITION BY RANGE (JOBID)
PARTITION FACT_TABLE_1110500 VALUES LESS THAN ('01110600')
LOGGING
NOCOMPRESS
TABLESPACE PSAPFACTTABLED
PCTFREE 10
INITRANS 11
MAXTRANS 255
STORAGE (
INITIAL 32248K
MINEXTENTS 1
MAXEXTENTS 2147483645
BUFFER_POOL DEFAULT
PARTITION FACT_TABLE_1191800 VALUES LESS THAN ('0119190000')
LOGGING
NOCOMPRESS
TABLESPACE PSAPFACTTABLED
PCTFREE 10
INITRANS 11
MAXTRANS 255
CREATE UNIQUE INDEX "FACT_TABLE~0" ON FACT_TABLE
(JOBID, RECID)
TABLESPACE PSAPFACT_TABLEI
INITRANS 2
MAXTRANS 255
LOCAL (
PARTITION FACT_TABLE_11105
LOGGING
NOCOMPRESS
TABLESPACE PSAPFACT_TABLEI
PCTFREE 10
INITRANS 2
MAXTRANS 255
STORAGE (
INITIAL 64K
MINEXTENTS 1
MAXEXTENTS 2147483645
BUFFER_POOL DEFAULT
...................................................... -
How to improve Query performance on large table in MS SQL Server 2008 R2
I have a table with 20 million records. What is the best option to improve query performance on this table. Is partitioning the table into filegroups is a best option or splitting the table into multiple smaller tables?
Hi bala197164,
First, I want to inform that both to partition the table into filegroups and split the table into multiple smaller tables can improve the table query performance, and they are fit for different situation. For example, our table have one hundred columns and
some columns are not related to this table object directly (for example, there is a table named userinfo to store user information, it has columns address_street, address_zip,address_ province columns, at this time, we can create a new table named as Address,
and add a foreign key in userinfo table references Address table), under this situation, by splitting a large table into smaller, individual tables, queries that access only a fraction of the data can run faster because there is less data to scan. Another
situation is our table records can be grouped easily, for example, there is a column named year to store information about product release date, at this time, we can partition the table into filegroups to improve the query performance. Usually, we perform
both of methods together. Additionally, we can add index to table to improve the query performance. For more detail information, please refer to the following document:
Partitioning:
http://msdn.microsoft.com/en-us/library/ms178148.aspx
CREATE INDEX (Transact-SQL):
http://msdn.microsoft.com/en-us/library/ms188783.aspx
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TechNet Community Support -
Slow query due to large table and full table scan
Hi,
We have a large Oracle database, v 10g. Two of the tables in the database have over one million rows.
We have a few queries which take a lot of time to execute. Not always though, it that seems when load is high the queries tend
to take much longer. Average time may be 1 or 2 seconds, but maxtime can be up to 2 minutes.
We have now used Oracle Grid to help us examine the queries. We have found that some of the queries require two or three full table scans.
Two of the full table scans are of the two large tables mentioned above.
This is an example query:
SELECT table1.column, table2.column, table3.column
FROM table1
JOIN table2 on table1.table2Id = table2.id
LEFT JOIN table3 on table2.table3id = table3.id
WHERE table1.id IN(
SELECT id
FROM (
(SELECT a.*, rownum rnum FROM(
SELECT table1.id
FROM table1,
table2,
table3
WHERE
table1.table2id = table2.id
AND
table2.table3id IS NULL OR table2.table3id = :table3IdParameter
) a
WHERE rownum <= :end))
WHERE rnum >= :start
Table1 and table2 are the large tables in this example. This query starts two full table scans on those tables.
Can we avoid this? We have, what we think are, the correct indexes.
/best regards, Håkan>
Hi Håkan - welcome to the forum.
We have a large Oracle database, v 10g. Two of the tables in the database have over one million rows.
We have a few queries which take a lot of time to execute. Not always though, it that seems when load is high the queries tend
to take much longer. Average time may be 1 or 2 seconds, but maxtime can be up to 2 minutes.
We have now used Oracle Grid to help us examine the queries. We have found that some of the queries require two or three full table scans.
Two of the full table scans are of the two large tables mentioned above.
This is an example query:Firstly, please read the forum FAQ - top right of page.
Please format your SQL using tags [code /code].
In order to help us to help you.
Please post table structures - relevant (i.e. joined, FK, PK fields only) in the form - note use of code tags - we can just run table create script.
CREATE TABLE table1
Field1 Type1,
Field2 Type2,
FieldN TypeN
);Then give us some table data - not 100's of records - just enough in the form
INSERT INTO Table1 VALUES(Field1, Field2.... FieldN);
..Please post EXPLAIN PLAN - again with tags.
HTH,
Paul...
/best regards, Håkan -
How to subdivide 1 large TABLE based on the output of a VIEW
I am searching for a decent method / example code to subdivide a large table (into a global temp table (GTT) for further processing) based on a list of numeric/alphanumeric which is the resultset from a view.
I am groping with the following strategy in PL/SQL:
1 -- set up cursor, execute the view (so I have the list of identifiers)
2 -- create a second cursor (or loop?) which:
accepts each of the identifiers in turn
executes a query (EXECUTE IMMEDIATE?) on the larger table
INSERTs (or appends?) each resultset into the GTT
3 -- Then the GTT contains just the requires subset of the larger table for further processing and eventual import into iReport for reporting.
Can anyone point me to code that would "spoon feed" me on this? Or suggest the best / better way to go about it?
The scale of the issue here -- GTT is defined and ready to go, the larger table contains approx 40,000 rows and I need to extract a dozen subsets or so which add up to approx 1000 rows.
Thanks,
RobWelcome to the forum!
>
I am searching for a decent method / example code to subdivide a large table (into a global temp table (GTT) for further processing) based on a list of numeric/alphanumeric which is the resultset from a view.
Can anyone point me to code that would "spoon feed" me on this? Or suggest the best / better way to go about it?
The scale of the issue here -- GTT is defined and ready to go, the larger table contains approx 40,000 rows and I need to extract a dozen subsets or so which add up to approx 1000 rows.
>
No - there is no code to point you to.
As many of the previous responses indicate part of the concern is that you seem to have already chosen and partially implemented a solution but the information you provided makes us question whether you have adequately analyzed and defined the actual problem and processing that needs to happen. Here's why I have questions about your approach
1. GTT - a red flag issue - these tables are generally not needed in Oracle. So when you, or anyone says they plan to use one it raises a red flag. People want to be sure you really need one rather than not using a table at all, or just using a regular table instead of a GTT.
2. Double nested CURSOR loops - a DOUBLE red flag issue - this is almost always SLOW-BY-SLOW (row-by-row) processing at its worst. It is seldom needed, doesn't perform well and won't scale. People are going to question this choice and rightfully so.
3. EXECUTE IMMEDIATE - a red flag issue or at least a yellow/warning flag. This is definitely a legitimate methodology when it is needed but may times developers resort to it when it isn't needed because it seems easier than doing the hard work of actually defining ALL of the requirements. It seems easier because it appears that it will allow and work for those 'unexpected' things that seem to come up in new development.
Unfortunately most of those unexpected things come up because the developer did not adequately define all of the requirements. The code may execute when those things arise but it likely won't do the right thing.
Seeing all three of those red flag issues in the same question is like waving a red flag at a charging bull. The responses you get are all likely to be of the 'DO NOT DO THAT' variety.
You are correct that a work table is appropriate when there is business logic to be applied to a set of data that cannot be applied using SQL alone. Use a regular table unless
1. you plan to have multiple sessions working with the table simutaneously,
2. each session needs to work with ONLY their own data in that table and not data from other sessions
3. the data does NOT need to be available after the session ends
4. you actually need a GTT to take advantage of the automatic data preservation (ON COMMIT PRESERVE/DELETE) functionality
Remember - when a session ends the data in the GTT is gone. That can makek it very difficult to troubleshoot data related problems since a different session can't see what data is in the table. Even if a GTT is needed for the final product it is very useful to use a regular table so that the data can be examined after test runs to help find and fix problems. Then after development is complete and initial testing is done a GTT would be substituted and final testing performed.
So the main remaining question is why you need to perform multiple dynamic queries to get the data populated into the work table? Especially why is a nested cursor loop needed? My suspicion is that you have the queries stored in a query table and one of your loops extracts the query and executes it dynamically.
How many queries are we talking about? Do these queries change from run to run? Please provide more detail of the process and an example query for the selection filtering as well as a typical dynamic query you plan to use. -
Pagination query help needed for large table - force a different index
I'm using a slight modification of the pagination query from over at Ask Tom's: [http://www.oracle.com/technology/oramag/oracle/07-jan/o17asktom.html]
Mine looks like this when fetching the first 100 rows of all members with last name Smith, ordered by join date:
SELECT members.*
FROM members,
SELECT RID, rownum rnum
FROM
SELECT rowid as RID
FROM members
WHERE last_name = 'Smith'
ORDER BY joindate
WHERE rownum <= 100
WHERE rnum >= 1
and RID = members.rowidThe difference between this and the one at Ask Tom's is that my innermost query just returns the ROWID. Then in the outermost query we join the ROWIDs returned to the members table, after we have pruned the ROWIDs down to only the chunk of 100 we want. This makes it MUCH faster (verifiably) on our large tables, as it is able to use the index on the innermost query (well... read on).
The problem I have is this:
SELECT rowid as RID
FROM members
WHERE last_name = 'Smith'
ORDER BY joindateThis will use the index for the predicate column (last_name) instead of the unique index I have defined for the joindate column (joindate, sequence). (Verifiable with explain plan). It is much slower this way on a large table. So I can hint it using either of the following methods:
SELECT /*+ index(members, joindate_idx) */ rowid as RID
FROM members
WHERE last_name = 'Smith'
ORDER BY joindate
SELECT /*+ first_rows(100) */ rowid as RID
FROM members
WHERE last_name = 'Smith'
ORDER BY joindateEither way, it now uses the index of the ORDER BY column (joindate_idx), so now it is much faster as it does not have to do a sort (remember, VERY large table, millions of records). So that seems good. But now, on my outermost query, I join the rowid with the meaningful columns of data from the members table, as commented below:
SELECT members.* -- Select all data from members table
FROM members, -- members table added to FROM clause
SELECT RID, rownum rnum
FROM
SELECT /*+ index(members, joindate_idx) */ rowid as RID -- Hint is ignored now that I am joining in the outer query
FROM members
WHERE last_name = 'Smith'
ORDER BY joindate
WHERE rownum <= 100
WHERE rnum >= 1
and RID = members.rowid -- Merge the members table on the rowid we pulled from the inner queriesOnce I do this join, it goes back to using the predicate index (last_name) and has to perform the sort once it finds all matching values (which can be a lot in this table, there is high cardinality on some columns).
So my question is, in the full query above, is there any way I can get it to use the ORDER BY column for indexing to prevent it from having to do a sort? The join is what causes it to revert back to using the predicate index, even with hints. Remove the join and just return the ROWIDs for those 100 records and it flies, even on 10 million records.
It'd be great if there was some generic hint that could accomplish this, such that if we change the table/columns/indexes, we don't need to change the hint (the FIRST_ROWS hint is a good example of this, while the INDEX hint is the opposite), but any help would be appreciated. I can provide explain plans for any of the above if needed.
Thanks!Lakmal Rajapakse wrote:
OK here is an example to illustrate the advantage:
SQL> set autot traceonly
SQL> select * from (
2 select a.*, rownum x from
3 (
4 select a.* from aoswf.events a
5 order by EVENT_DATETIME
6 ) a
7 where rownum <= 1200
8 )
9 where x >= 1100
10 /
101 rows selected.
Execution Plan
Plan hash value: 3711662397
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
| 0 | SELECT STATEMENT | | 1200 | 521K| 192 (0)| 00:00:03 |
|* 1 | VIEW | | 1200 | 521K| 192 (0)| 00:00:03 |
|* 2 | COUNT STOPKEY | | | | | |
| 3 | VIEW | | 1200 | 506K| 192 (0)| 00:00:03 |
| 4 | TABLE ACCESS BY INDEX ROWID| EVENTS | 253M| 34G| 192 (0)| 00:00:03 |
| 5 | INDEX FULL SCAN | EVEN_IDX02 | 1200 | | 2 (0)| 00:00:01 |
Predicate Information (identified by operation id):
1 - filter("X">=1100)
2 - filter(ROWNUM<=1200)
Statistics
0 recursive calls
0 db block gets
443 consistent gets
0 physical reads
0 redo size
25203 bytes sent via SQL*Net to client
281 bytes received via SQL*Net from client
8 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
101 rows processed
SQL>
SQL>
SQL> select * from aoswf.events a, (
2 select rid, rownum x from
3 (
4 select rowid rid from aoswf.events a
5 order by EVENT_DATETIME
6 ) a
7 where rownum <= 1200
8 ) b
9 where x >= 1100
10 and a.rowid = rid
11 /
101 rows selected.
Execution Plan
Plan hash value: 2308864810
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
| 0 | SELECT STATEMENT | | 1200 | 201K| 261K (1)| 00:52:21 |
| 1 | NESTED LOOPS | | 1200 | 201K| 261K (1)| 00:52:21 |
|* 2 | VIEW | | 1200 | 30000 | 260K (1)| 00:52:06 |
|* 3 | COUNT STOPKEY | | | | | |
| 4 | VIEW | | 253M| 2895M| 260K (1)| 00:52:06 |
| 5 | INDEX FULL SCAN | EVEN_IDX02 | 253M| 4826M| 260K (1)| 00:52:06 |
| 6 | TABLE ACCESS BY USER ROWID| EVENTS | 1 | 147 | 1 (0)| 00:00:01 |
Predicate Information (identified by operation id):
2 - filter("X">=1100)
3 - filter(ROWNUM<=1200)
Statistics
8 recursive calls
0 db block gets
117 consistent gets
0 physical reads
0 redo size
27539 bytes sent via SQL*Net to client
281 bytes received via SQL*Net from client
8 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
101 rows processed
Lakmal (and OP),
Not sure what advantage you are trying to show here. But considering that we are talking about pagination query here and order of records is important, your 2 queries will not always generate output in same order. Here is the test case:
SQL> select * from v$version ;
BANNER
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Prod
PL/SQL Release 10.2.0.1.0 - Production
CORE 10.2.0.1.0 Production
TNS for Linux: Version 10.2.0.1.0 - Production
NLSRTL Version 10.2.0.1.0 - Production
SQL> show parameter optimizer
NAME TYPE VALUE
optimizer_dynamic_sampling integer 2
optimizer_features_enable string 10.2.0.1
optimizer_index_caching integer 0
optimizer_index_cost_adj integer 100
optimizer_mode string ALL_ROWS
optimizer_secure_view_merging boolean TRUE
SQL> show parameter pga
NAME TYPE VALUE
pga_aggregate_target big integer 103M
SQL> create table t nologging as select * from all_objects where 1 = 2 ;
Table created.
SQL> create index t_idx on t(last_ddl_time) nologging ;
Index created.
SQL> insert /*+ APPEND */ into t (owner, object_name, object_id, created, last_ddl_time) select owner, object_name, object_id, created, sysdate - dbms_random.value(1, 100) from all_objects order by dbms_random.random;
40617 rows created.
SQL> commit ;
Commit complete.
SQL> exec dbms_stats.gather_table_stats(user, 'T', cascade=>true);
PL/SQL procedure successfully completed.
SQL> select object_id, object_name, created from t, (select rid, rownum rn from (select rowid rid from t order by created desc) where rownum <= 1200) t1 where rn >= 1190 and t.rowid = t1.rid ;
OBJECT_ID OBJECT_NAME CREATED
47686 ALL$OLAP2_JOIN_KEY_COLUMN_USES 28-JUL-2009 08:08:39
47672 ALL$OLAP2_CUBE_DIM_USES 28-JUL-2009 08:08:39
47681 ALL$OLAP2_CUBE_MEASURE_MAPS 28-JUL-2009 08:08:39
47682 ALL$OLAP2_FACT_LEVEL_USES 28-JUL-2009 08:08:39
47685 ALL$OLAP2_AGGREGATION_USES 28-JUL-2009 08:08:39
47692 ALL$OLAP2_CATALOGS 28-JUL-2009 08:08:39
47665 ALL$OLAPMR_FACTTBLKEYMAPS 28-JUL-2009 08:08:39
47688 ALL$OLAP2_DIM_LEVEL_ATTR_MAPS 28-JUL-2009 08:08:39
47689 ALL$OLAP2_DIM_LEVELS_KEYMAPS 28-JUL-2009 08:08:39
47669 ALL$OLAP9I2_HIER_DIMENSIONS 28-JUL-2009 08:08:39
47666 ALL$OLAP9I1_HIER_DIMENSIONS 28-JUL-2009 08:08:39
11 rows selected.
SQL> select object_id, object_name, last_ddl_time from t, (select rid, rownum rn from (select rowid rid from t order by last_ddl_time desc) where rownum <= 1200) t1 where rn >= 1190 and t.rowid = t1.rid ;
OBJECT_ID OBJECT_NAME LAST_DDL_TIME
11749 /b9fe5b99_OraRTStatementComman 06-FEB-2010 03:43:49
13133 oracle/jdbc/driver/OracleLog$3 06-FEB-2010 03:45:44
37534 com/sun/mail/smtp/SMTPMessage 06-FEB-2010 03:46:14
36145 /4e492b6f_SerProfileToClassErr 06-FEB-2010 03:11:09
26815 /7a628fb8_DefaultHSBChooserPan 06-FEB-2010 03:26:55
16695 /2940a364_RepIdDelegator_1_3 06-FEB-2010 03:38:17
36539 sun/io/ByteToCharMacHebrew 06-FEB-2010 03:28:57
14044 /d29b81e1_OldHeaders 06-FEB-2010 03:12:12
12920 /25f8f3a5_BasicSplitPaneUI 06-FEB-2010 03:11:06
42266 SI_GETCLRHSTGRFTR 06-FEB-2010 03:40:20
15752 /2f494dce_JDWPThreadReference 06-FEB-2010 03:09:31
11 rows selected.
SQL> select object_id, object_name, last_ddl_time from (select t1.*, rownum rn from (select * from t order by last_ddl_time desc) t1 where rownum <= 1200) where rn >= 1190 ;
OBJECT_ID OBJECT_NAME LAST_DDL_TIME
37534 com/sun/mail/smtp/SMTPMessage 06-FEB-2010 03:46:14
13133 oracle/jdbc/driver/OracleLog$3 06-FEB-2010 03:45:44
11749 /b9fe5b99_OraRTStatementComman 06-FEB-2010 03:43:49
42266 SI_GETCLRHSTGRFTR 06-FEB-2010 03:40:20
16695 /2940a364_RepIdDelegator_1_3 06-FEB-2010 03:38:17
36539 sun/io/ByteToCharMacHebrew 06-FEB-2010 03:28:57
26815 /7a628fb8_DefaultHSBChooserPan 06-FEB-2010 03:26:55
14044 /d29b81e1_OldHeaders 06-FEB-2010 03:12:12
36145 /4e492b6f_SerProfileToClassErr 06-FEB-2010 03:11:09
12920 /25f8f3a5_BasicSplitPaneUI 06-FEB-2010 03:11:06
15752 /2f494dce_JDWPThreadReference 06-FEB-2010 03:09:31
11 rows selected.
SQL> select object_id, object_name, last_ddl_time from t, (select rid, rownum rn from (select rowid rid from t order by last_ddl_time desc) where rownum <= 1200) t1 where rn >= 1190 and t.rowid = t1.rid order by last_ddl_time desc ;
OBJECT_ID OBJECT_NAME LAST_DDL_TIME
37534 com/sun/mail/smtp/SMTPMessage 06-FEB-2010 03:46:14
13133 oracle/jdbc/driver/OracleLog$3 06-FEB-2010 03:45:44
11749 /b9fe5b99_OraRTStatementComman 06-FEB-2010 03:43:49
42266 SI_GETCLRHSTGRFTR 06-FEB-2010 03:40:20
16695 /2940a364_RepIdDelegator_1_3 06-FEB-2010 03:38:17
36539 sun/io/ByteToCharMacHebrew 06-FEB-2010 03:28:57
26815 /7a628fb8_DefaultHSBChooserPan 06-FEB-2010 03:26:55
14044 /d29b81e1_OldHeaders 06-FEB-2010 03:12:12
36145 /4e492b6f_SerProfileToClassErr 06-FEB-2010 03:11:09
12920 /25f8f3a5_BasicSplitPaneUI 06-FEB-2010 03:11:06
15752 /2f494dce_JDWPThreadReference 06-FEB-2010 03:09:31
11 rows selected.
SQL> set autotrace traceonly
SQL> select object_id, object_name, last_ddl_time from t, (select rid, rownum rn from (select rowid rid from t order by last_ddl_time desc) where rownum <= 1200) t1 where rn >= 1190 and t.rowid = t1.rid order by last_ddl_time desc
2 ;
11 rows selected.
Execution Plan
Plan hash value: 44968669
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
| 0 | SELECT STATEMENT | | 1200 | 91200 | 180 (2)| 00:00:03 |
| 1 | SORT ORDER BY | | 1200 | 91200 | 180 (2)| 00:00:03 |
|* 2 | HASH JOIN | | 1200 | 91200 | 179 (2)| 00:00:03 |
|* 3 | VIEW | | 1200 | 30000 | 98 (0)| 00:00:02 |
|* 4 | COUNT STOPKEY | | | | | |
| 5 | VIEW | | 40617 | 475K| 98 (0)| 00:00:02 |
| 6 | INDEX FULL SCAN DESCENDING| T_IDX | 40617 | 793K| 98 (0)| 00:00:02 |
| 7 | TABLE ACCESS FULL | T | 40617 | 2022K| 80 (2)| 00:00:01 |
Predicate Information (identified by operation id):
2 - access("T".ROWID="T1"."RID")
3 - filter("RN">=1190)
4 - filter(ROWNUM<=1200)
Statistics
1 recursive calls
0 db block gets
348 consistent gets
0 physical reads
0 redo size
1063 bytes sent via SQL*Net to client
385 bytes received via SQL*Net from client
2 SQL*Net roundtrips to/from client
1 sorts (memory)
0 sorts (disk)
11 rows processed
SQL> select object_id, object_name, last_ddl_time from (select t1.*, rownum rn from (select * from t order by last_ddl_time desc) t1 where rownum <= 1200) where rn >= 1190 ;
11 rows selected.
Execution Plan
Plan hash value: 882605040
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
| 0 | SELECT STATEMENT | | 1200 | 62400 | 80 (2)| 00:00:01 |
|* 1 | VIEW | | 1200 | 62400 | 80 (2)| 00:00:01 |
|* 2 | COUNT STOPKEY | | | | | |
| 3 | VIEW | | 40617 | 1546K| 80 (2)| 00:00:01 |
|* 4 | SORT ORDER BY STOPKEY| | 40617 | 2062K| 80 (2)| 00:00:01 |
| 5 | TABLE ACCESS FULL | T | 40617 | 2062K| 80 (2)| 00:00:01 |
Predicate Information (identified by operation id):
1 - filter("RN">=1190)
2 - filter(ROWNUM<=1200)
4 - filter(ROWNUM<=1200)
Statistics
0 recursive calls
0 db block gets
343 consistent gets
0 physical reads
0 redo size
1063 bytes sent via SQL*Net to client
385 bytes received via SQL*Net from client
2 SQL*Net roundtrips to/from client
1 sorts (memory)
0 sorts (disk)
11 rows processed
SQL> select object_id, object_name, last_ddl_time from t, (select rid, rownum rn from (select rowid rid from t order by last_ddl_time desc) where rownum <= 1200) t1 where rn >= 1190 and t.rowid = t1.rid ;
11 rows selected.
Execution Plan
Plan hash value: 168880862
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
| 0 | SELECT STATEMENT | | 1200 | 91200 | 179 (2)| 00:00:03 |
|* 1 | HASH JOIN | | 1200 | 91200 | 179 (2)| 00:00:03 |
|* 2 | VIEW | | 1200 | 30000 | 98 (0)| 00:00:02 |
|* 3 | COUNT STOPKEY | | | | | |
| 4 | VIEW | | 40617 | 475K| 98 (0)| 00:00:02 |
| 5 | INDEX FULL SCAN DESCENDING| T_IDX | 40617 | 793K| 98 (0)| 00:00:02 |
| 6 | TABLE ACCESS FULL | T | 40617 | 2022K| 80 (2)| 00:00:01 |
Predicate Information (identified by operation id):
1 - access("T".ROWID="T1"."RID")
2 - filter("RN">=1190)
3 - filter(ROWNUM<=1200)
Statistics
0 recursive calls
0 db block gets
349 consistent gets
0 physical reads
0 redo size
1063 bytes sent via SQL*Net to client
385 bytes received via SQL*Net from client
2 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
11 rows processed
SQL> select object_id, object_name, last_ddl_time from (select t1.*, rownum rn from (select * from t order by last_ddl_time desc) t1 where rownum <= 1200) where rn >= 1190 order by last_ddl_time desc ;
11 rows selected.
Execution Plan
Plan hash value: 882605040
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
| 0 | SELECT STATEMENT | | 1200 | 62400 | 80 (2)| 00:00:01 |
|* 1 | VIEW | | 1200 | 62400 | 80 (2)| 00:00:01 |
|* 2 | COUNT STOPKEY | | | | | |
| 3 | VIEW | | 40617 | 1546K| 80 (2)| 00:00:01 |
|* 4 | SORT ORDER BY STOPKEY| | 40617 | 2062K| 80 (2)| 00:00:01 |
| 5 | TABLE ACCESS FULL | T | 40617 | 2062K| 80 (2)| 00:00:01 |
Predicate Information (identified by operation id):
1 - filter("RN">=1190)
2 - filter(ROWNUM<=1200)
4 - filter(ROWNUM<=1200)
Statistics
175 recursive calls
0 db block gets
388 consistent gets
0 physical reads
0 redo size
1063 bytes sent via SQL*Net to client
385 bytes received via SQL*Net from client
2 SQL*Net roundtrips to/from client
4 sorts (memory)
0 sorts (disk)
11 rows processed
SQL> set autotrace off
SQL> spool offAs you will see, the join query here has to have an ORDER BY clause at the end to ensure that records are correctly sorted. You can not rely on optimizer choosing NESTED LOOP join method and, as above example shows, when optimizer chooses HASH JOIN, oracle is free to return rows in no particular order.
The query that does not involve join always returns rows in the desired order. Adding an ORDER BY does add a step in the plan for the query using join but does not affect the other query. -
Slow performance for large queries
Hi -
I'm experiencing slow performance when I use a filter with a very large OR clause.
I have a list of users, whose uid's are known, and I want to retrieve attributes for all users. If I do this one at a time, I pay the network overhead, and this becomes a bottleneck. However, if I try to get information about all users at once, the query runs ridiculously slow - ~ 10minutes for 5000 users.
The syntax of my filter is: (|(uid=user1)(uid=user2)(uid=user3)(uid=user4).....(uid=user5000))
I'm trying this technique because it's similar to good design for oracle - minimizing round trips to the database.
I'm running LDAP 4.1.1 on a Tru64 OS - v5.1.This is a performance/tuning forum for iPlanet Application Server. You'd have better luck with this question on the Directory forum.
The directory folks don't have a separate forum dedicated to tuning, but they answer performance questions in the main forum all of the time.
David -
Slow Performance or XDP File size very large
There have been a few reports of people having slow performance in their forms (tyically for Dynamic forms) or file sizes of XDP files being very large.
These are the symptoms of a problem with cut and paste in Designer where a Process Instruction (PI) used to control how Designer displays a specific palette is repeated many many times. If you look in your XDP source and see this line repeated more than once then you have the issue:
The problem has been resolved by applying a style sheet to the XDP and removing the instruction (until now). A patch has been released that will fix the cut and paste issue as well as repair your templates when you open them in a designer with the patch applied.
Here is a blog entry that describes the patch as well as where to get it.
http://blogs.adobe.com/livecycle/2009/03/post.htmlMy XDP file grow up to 145mb before i decided to see what was actually happening.
It appears that the LvieCycle Designer ES program sometimes writes alot of redundant data... the same line millions of times over & over again.
I wrote this small java program which reduced the size up to 111KB !!!!!!!!!!!!!!!!!! (wow what a bug that must have been!!!)
Here's the sourcecode:
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
public class MakeSmaller {
private static final String DELETE_STRING = " <?templateDesigner StyleID aped3?>";
public static void main(String... args) {
BufferedReader br = null;
BufferedWriter bw = null;
try {
br = new BufferedReader(new FileReader(args[0]));
bw = new BufferedWriter(new BufferedWriter(new FileWriter(args[0] + ".small")));
String line = null;
boolean firstOccurence = true;
while((line = br.readLine()) != null) {
if (line.equals(DELETE_STRING)) {
if (firstOccurence) {
bw.write(line + "\n");
firstOccurence = false;
} else {
bw.write(line + "\n");
firstOccurence = true;
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (br != null) {
try {
br.close();
} catch (IOException e) {
e.printStackTrace();
if (bw != null) {
try {
bw.close();
} catch (IOException e) {
e.printStackTrace();
File that gets generated is the same as the xdp file (same location) but gets the extension .small. Just in case something goes wrong the original file is NOT modified as you can see in the source code. And yes Designer REALLY wrote that line like a gazillion times in the .xdp file (shame on the programmers!!)
You can also see that i also write the first occurrence to the small file just in case its needed... -
Need help in optimisation for a select query on a large table
Hi Gurus
Please help in optimising the code. It takes 1 hr for 3-4000 records. Its very slow.
My Select is reading from a table which contains 10 Million records.
I am writing the select on large table and Retrieving the values from large tables by comparing my table which has 3-4 k records.
I am pasting the code. please help
Data: wa_i_tab1 type tys_tg_1 .
DATA: i_tab TYPE STANDARD TABLE OF tys_tg_1.
Data : wa_result_pkg type tys_tg_1,
wa_result_pkg1 type tys_tg_1.
SELECT /BIC/ZSETLRUN AGREEMENT /BIC/ZREB_SDAT /BIC/ZLITEM1 from
/BIC/PZREB_SDAT *******************THIS TABLE CONTAINS 10 MILLION RECORDS
into CORRESPONDING FIELDS OF table i_tab
FOR ALL ENTRIES IN RESULT_PACKAGE***************CONTAINS 3000-4000 RECORDS
where
/bic/ZREB_SDAT = RESULT_PACKAGE-/BIC/ZREB_SDAT
AND
AGREEMENT = RESULT_PACKAGE-AGREEMENT
AND /BIC/ZLITEM1 = RESULT_PACKAGE-/BIC/ZLITEM1.
sort RESULT_PACKAGE by AGREEMENT /BIC/ZREB_SDAT /BIC/ZLITEM1.
sort i_tab by AGREEMENT /BIC/ZREB_SDAT /BIC/ZLITEM1.
loop at RESULT_PACKAGE into wa_result_pkg.
read TABLE i_tab INTO wa_i_tab1 with key
/BIC/ZREB_SDAT =
wa_result_pkg-/BIC/ZREB_SDAT
AGREEMENT = wa_result_pkg-AGREEMENT
/BIC/ZLITEM1 = wa_result_pkg-/BIC/ZLITEM1.
IF SY-SUBRC = 0.
move wa_i_tab1-/BIC/ZSETLRUN to
wa_result_pkg-/BIC/ZSETLRUN.
wa_result_pkg1-/BIC/ZSETLRUN = wa_result_pkg-/BIC/ZSETLRUN.
modify RESULT_PACKAGE from wa_result_pkg1
TRANSPORTING /BIC/ZSETLRUN.
ENDIF.
CLEAR: wa_i_tab1,wa_result_pkg1,wa_result_pkg.
endloop.Hi,
1) RESULT_PACKAGE internal table contains any duplicate records or not bassed on the where condotion like below
2) Remove the into CORRESPONDING FIELDS OF table instead of that into table use.
refer the below code is
RESULT_PACKAGE1[] = RESULT_PACKAGE[].
sort RESULT_PACKAGE1 by /BIC/ZREB_SDAT AGREEMENT /BIC/ZLITEM1.
delete adjustant duplicate form RESULT_PACKAGE1 comparing /BIC/ZREB_SDAT AGREEMENT /BIC/ZLITEM1.
SELECT /BIC/ZSETLRUN AGREEMENT /BIC/ZREB_SDAT /BIC/ZLITEM1
from /BIC/PZREB_SDAT
into table i_tab
FOR ALL ENTRIES IN RESULT_PACKAGE1
where
/bic/ZREB_SDAT = RESULT_PACKAGE1-/BIC/ZREB_SDAT
AND
AGREEMENT = RESULT_PACKAGE1-AGREEMENT
AND /BIC/ZLITEM1 = RESULT_PACKAGE1-/BIC/ZLITEM1.
and one more thing your getting 10 million records so use package size in you select query.
Refer the following link also For All Entry for 1 Million Records
Regards,
Dhina..
Edited by: Dhina DMD on Sep 15, 2011 7:17 AM -
Performance during joining large tables
Hi,
I have to maintain a report which gets data from many large tables as below. Currently it is using join statement to join all 8 tables and causing a very slow performance.
SELECT
into corresponding fields of table equip
FROM caufv
join afih on afih~aufnr = caufv~aufnr
join iloa on iloa~iloan = afih~iloan
join iflos on iflos~tplnr = iloa~tplnr
join iflotx on iflos~tplnr = iflotx~tplnr
join vbak on vbak~aufnr = caufv~aufnr
join equz on equz~equnr = afih~equnr
join equi on equi~equnr = equz~equnr
join vbap on vbak~vbeln = vbap~vbeln
WHERE
Please suggest me another way, I'm newbie in ABAP. I tried using FOR ALL ENTRIES IN but it did not work. I would very appreciate if you can leave me some sample lines of code.
Thanks,Hi Dear ,
I will suggest you not to use inner join for such i.e. 8 number of table and that too huge tables. Instead use For All entries wherever possible. But before using for all entries check initial for base table and if its not possible to avoid inner join then try to minimise it. Use inner join between header and item.
Hope this will help you to solve your problem . Feel free to ask if you have any doubt.
Regards,
Vijay -
How to query a table join in SAP?
Hi,
We are rolling out SAP and our abapers are wondering how to debug production problems. From our experience with PeopleSoft, there is often a need to query tables directly in production. These queries are often joins. SAP provides SE16 to query a single table, but how to SDN'ers query a join in PROD?
For a basic example, how would you join a sales item and sales header? We are thinking of using Oracle OpenSQL to have direct table access. Solutions that somehow use SAP security for developers to access production are good!
Any suggestions are welcome and points will be rewarded!!
PeterPeter,
Be careful if your company is large enough to have been impacted by Sarbanes-Oxley 404. Your external auditing firm should be engaged in whatever approach you take.
This type of information/querying is now much more monitored/controlled for SOX 404-impacted organizations.
Example - SQVI has been removed from all PRD instances in our company b/c of SOX 404. -
Partitioning - query on large table v. query accessing several partitions
Hi,
We are using partitioning on a large fact table, however, in deciding partitioning strategy looking for advice regarding queries which have to access several partitions versus query against a large table.
What is quicker - a query which acccesses a large table or a query which accesseses several partitions to return results. I
Need to partition due to size/admin etc. but want to make sure queries which need to access > 1 partition are not significantly slower than ones which access a large table by comparison.
Ones which access just one partition fine but some queries have to accesse several partitions
Many ThanksHere are your choices stated another way. Is it better to:
1. Get one weeks data by reading one month's data and throwing away 75% of it (assumes partitioning by month)
2. Get one weeks data by reading three weeks of it and throwing away part of two weeks? (assumes partitioning by week)
3. Get one weeks data by reading seven daily partitions and not having to throw away any of it? (assumes daily partitioning)
I have partitioned as frequently as every 5-15 minutes (banking and telecom) and have yet to find a situation where partitions larger than the minimum date-range for the majority of queries makes sense.
Anyone can insert data into a table ... an extra millisecond per insert is generally irrelevant. What you want to do is optimize reading the data where that extra millisecond per row, over millions of rows, adds up to measurable time.
But this is Oracle so the best answer to your questions is to recommend you not take anyone advice on this but rather run some tests with real data, in real-world volumes, with real-world DML and queries.
Maybe you are looking for
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When I run two reports, I am getting the following errors:5200--Error Executing Query 796 Error Executing Query 69Any Ideas?ThanksJim
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Where is the Help Catalog stored?
In user form we can specify a Help Catalog which actually displays a help page when we click on help link on top right corner. For example, I see "user/enduser-help.xml" in Enable User Form. Anyway, I cannot see any enduser-help.xml under <idm>/user
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A group of people took an online webinar yesterday. The instructor is a heavy Adjustment Brush user, in LightRoom. After taking the class, many of the students in the group are reporting the appearance of weird blocks on images, after using the Adj
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Sharing one monitor and keyboard with two Macs
Hi, I have two Macs - one Pro and one G5. I want to be able to use both easily, using just one keyboard and monitor. Can anyone recommend the best way of doing this, and what splitter I should buy? Thanks!