Single table growth

Hello Gurus,
We can see one of the "custom" table in our system is growing quite fast. From the current trend I can see it is growing 1-3 GB pe rday. We are not in a position to stop the relevant program due to the impact on Business. We are in the process of finding the solution for that. However I wanted to understand if this table is growing too fast does that impact on the over all system performance. It is given fact that if some one try to access this table then it would create a perofrmance problem (only for this specific table). My question more related overall perofrmance.
Taking a scenario when some one is updating this table (Which isgrowing too fast) and in the mean time other users are perofrming activities in other tables.
Many Thanks
Praveen Kumar

Hi,
1). You can archive the Older data from the table, if your business allows you.
2). Create Index depends on the query accessed.
3). I strongly recommend to run twice or daily STATS for the table using DB20.
Taking a scenario when some one is updating this table (Which isgrowing too fast) and in the mean time other users are perofrming activities in other tables.
Performance problem arises when multiple people using same table to read the DATA. (Archiving Older data and Statistics on table should fix the performance issues)
Here is the link for FAQ about archiving data.
http://www.sdn.sap.com/irj/scn/index?rid=/library/uuid/d76f5301-0b01-0010-2a97-9938052ddf81

Similar Messages

Creation of SAP Query in SQ02 with Single Table With Condition

Hi All,
I want to Create SAP Query in SQ02 using single Table MCHA.
ii) I dont want all entries of MCHA Table I mean , I have to apply some Condition on this Table.
i.e Suppose I am having actual data in MCHA table is like this for Material M1.
Plant    Material   Batch   BatchCreationdate
P1          M1         B1       20.06.2007
P2          M1         B1       04.05.2009
P3          M1         B1       04.05.2009
But I want the Output of SAP Query is like this:
   Material   Batch   BatchCreationdate
      M1         B1       20.06.2007
That is irrespective of Plant if Material & Batch are equal ---> 1st record with Lowest date shoud get at the output.
Please help me How write the code on single table in the SAP Query.
Thanks,
Kiran Manyam

Hi,
Your query should be like this:
Select MATNR CHARG HSDAT
from MCHA
into table t_mcha
where matnr = Materlal number from selection screen.
The structure of t_mcha should contain the fields that you select.
Then sort the table by date ascending
Sort t_mcha by HSDAT.
Hope this solves your problem.
Thanks,
Sowmya

CO table growth rate

Hi,
We have gone line with SAP ECC for retail scenario recently. Our database is growing 3 GB per day which includes both data and index growth.
Modules configured:
SD (Retail), MM, HR and FI/CO.
COPA is configured for reporting purpose to find article wise sales details per day and COPA summarization has not been done.
Total sales order created per day on an average: 4000
Total line items of sales order on an average per day: 25000
Total purchase order created per day on an avearage: 1000
Please suggest whether database growth of 3 GB per day is normal for our scenario or should we do something to restrict the database growth.
Fastest Growing tables are,
CE11000     Operating Concern fo
CE31000     Operating Concern fo
ACCTIT     Compressed Data from FI/CO Document
BSIS     Accounting: Secondary Index for G/L Accounts
GLPCA     EC-PCA: Actual Line Items
FAGLFLEXA      General Ledger: Actual Line Items
VBFA     Sales Document Flow
RFBLG     Cluster for accounting document
FAGL_SPLINFO     Splittling Information of Open Items
S120     Sales as per receipts
MSEG     Document Segment: Article
VBRP     Billing Document: Item Data
ACCTCR     Compressed Data from FI/CO Document - Currencies
CE41000_ACCT     Operating Concern fo
S033     Statistics: Movements for Current Stock (Individual Records)
EDIDS     Status Record (IDoc)
CKMI1     Index for Accounting Documents for Article
LIPS     SD document: Delivery: Item data
VBOX     SD Document: Billing Document: Rebate Index
VBPA     Sales Document: Partner
BSAS     Accounting: Secondary Index for G/L Accounts (Cleared Items)
BKPF     Accounting Document Header
FAGL_SPLINFO_VAL     Splitting Information of Open Item Values
VBAP     Sales Document: Item Data
KOCLU     Cluster for conditions in purchasing and sales
COEP     CO Object: Line Items (by Period)
S003     SIS: SalesOrg/DistCh/Division/District/Customer/Product
S124     Customer / article
SRRELROLES     Object Relationship Service: Roles
S001     SIS: Customer Statistics
Is there anyway we can reduce the datagrowth without affecting the functionalities configured?
Is COPA summarization configuration will help reducing the size of the FI/CO tables growth?
Regards,
Nalla.

user480060 wrote:
Dear all,
Oracle 9.2 on AIX 5.3
In one of our database, one table has a very fast growth rate.
How can I check if the table growth is normal or not.
Please advice
The question is, what is a "very fast growth rate"?
What are the DDL of the table resp. the data types that the table uses?
One potential issue could be the way the table is populated: If you constantly insert into the table using a direct-path insert (APPEND hint) and subsequently delete rows then your table will grow faster than required because the deleted rows won't be reused by the direct-path insert because it always writes above the current high-water mark of your table.
May be you want to check your application for such an case if you think that the table grows faster than the actual amount of data it contains.
You could use the ANALYZE command to get information about empty blocks and average free space in the blocks or use the procedures provided by DBMS_SPACE package to find out more about the current usage of your segment.
Regards,
Randolf
Oracle related stuff blog:
http://oracle-randolf.blogspot.com/
SQLTools++ for Oracle (Open source Oracle GUI for Windows):
http://www.sqltools-plusplus.org:7676/
http://sourceforge.net/projects/sqlt-pp/

How to display data from 2 different groups in a single table

Hi,
Following is the requirement:
The XML Content is below
ListOf_ssAssetMgmtAsset>
-<ssAssetMgmtAsset>
<ssAccountName>1-1D09-83031</ssAccountName>
<ssAccountPrimaryCountry>USA</ssAccountPrimaryCountry>
<ssAssetNumber>13111027</ssAssetNumber>
<ssNaiAssetNumber>123</ssNaiAssetNumber>
<ssNaiGrantNumber>ABC</ssNaiGrantNumber>
<ssNaiProductType>System Security Software</ssNaiProductType>
<ssNaiSuperceded>123</ssNaiSuperceded>
<ssProductDescription>Upgrade extract local DB</ssProductDescription>
<ssProductName>1-1M5H-296</ssProductName>
<ssStatus>ABC</ssStatus>
<ssId>1X-ZY</ssId>
<ssCreated>01/01/1980</ssCreated>
<ssUpdated>01/01/1980</ssUpdated>
<ssCreatedBy>1X-ZY</ssCreatedBy>
<ssUpdatedBy>1X-ZY</ssUpdatedBy>
-<ListOf_ssAgreementEntitlement>
-<ssAgreementEntitlement>
<ssEntitlementEndDate>16/12/2009</ssEntitlementEndDate>
<ssEntitlementStartDate>16/11/2009</ssEntitlementStartDate>
<ssEntitlementType>Services</ssEntitlementType>
<ssNaiQuantity>2</ssNaiQuantity>
</ssAgreementEntitlement>
</ListOf_ssAgreementEntitlement>
-<ListOf_ssAgreementEntitlement>
-<ssAgreementEntitlement>
<ssEntitlementEndDate>10/12/2009</ssEntitlementEndDate>
<ssEntitlementStartDate>10/11/2009</ssEntitlementStartDate>
<ssEntitlementType>ServicePortal</ssEntitlementType>
<ssNaiQuantity>1</ssNaiQuantity>
</ssAgreementEntitlement>
</ListOf_ssAgreementEntitlement>
</ssAssetMgmtAsset>
</ListOf_ssAssetMgmtAsset>
The data needs to be displayed in the below manner where first grouping is by Account Country, then by Account Name. Then the table with 9 columns where in the first 5 columns are from first group and the next 4 are from second group.
Account Country
Account Name
ProductType Grant # Asset # Product SKU Product Name Entitlement Type Quantity /Nodes EntitlementStart Date Entitlement EndDate
I have the coding as
first for loop: <?for-each-group:ssAssetMgmtAsset;./ssAccountPrimaryCountry?>
second for loop: <?for-each-group:current-group();./ssAccountName?>
third which is for the table : <?for-each:current-group()?>
I close the above grp after product description.
One table with the first 5 columns and below second table is placed adjacent to the first to display the 4 columns with the grp <?for-each:ssAgreementEntitlement?>
how do I get all the 9 columns in a single row in a single table.
Any help is appreciated.
thanks

What is the lnk between the two
ssAssetMgmtAsset and ssAgreementEntitlement ?
you want to display all the ssAgreementEntitlement for every ssAssetMgmtAsset group ?
there shud be a link between them, you have link them and display.

Why do we create multiple aliases to a single table?

<h4>{color:#0000ff}Hi,{color}</h4>
<h4></h4>
<h4></h4>
<h4>{color:#0000ff} Why do we create multiple aliases to a single table in the same query?{color}</h4>
<h4></h4>
<h4></h4>
<h4>{color:#0000ff}{color:#000000}For Ex: {color}{color}</h4>
<h4>
{color:#000000}select name,address,phone, from emp e, emp e1{color}</h4>
<h4></h4>
<h4>{color:#000000}where e.empid = e1.empid;{color}</h4>
<h4>
{color:#0000ff}ofcourse the above query's where condition is not correct, but i am giving as an example only{color}</h4>
<h4>{color:#0000ff}I have seen similar kind of queries where a single table name is aliased 10 times in the same query{color}</h4>
<h4>{color:#0000ff}can someone help me to understand the logic behind it?{color}</h4>
<h4>{color:#0000ff}Thanks in advance{color}</h4>
<h4>{color:#0000ff}greddy.{color}</h4>
Edited by: greddy on Oct 24, 2008 2:46 AM

Hi,
When you say
FROM    emp e
,       emp e1you are using two copies of the same table.
Can you imagine using two copies of the same book at the same time?
Say you see a word (like "hyrax") that you don't know. You might look up that word in the dictionary.
The English sentence "Open the dictionary to the page containing the new word." is like this SQL query:
FROM    dictionary
WHERE   :unknown_word BETWEEN low_guide_word and high_guide_wordWhat if you saw that word while reading a book (let's call it book_a).
You might want to leave book_a open, and place the dictionary beside book_a, so you can easily compare how the word is used in book_a with the definition in the dictionary.
This corresponds to joining two tables in SQL:
FROM    book_a
JOIN    dictionary ON unknown_word BETWEEN low_guide_word AND high_guide_word
WHERE   book_a.page = whatever -- NOTE: both tables have a column called pageor you can use aliases for one or both of the tables
FROM    book_a      a
JOIN    dictionary d ON a.unknown_word BETWEEN d.low_guide_word AND d.high_guide_word
WHERE   a.page = whatever -- NOTE: both tables have a column called pageNow, imagine that book_a is itself the dictionary. Say you saw the word "hyrax" while you were looking up another word, "ibex".
You can do a side-by-side comparison, as above, if you have two copies of the dictionary. Leave one copy open to "ibex", and open the other copy to "hyrax".
This corresponds to a self-join in SQL:
FROM    dictionary a
JOIN    dictionary d ON a.unknown_word BETWEEN d.low_guide_word AND d.high_guide_word
WHERE   a.page = whatever -- NOTE: both tables have a column called pageNotice that this last bit of code is identical to the previous one, except that book_a is replaced with dictionary.
In this case, you must you a table alias, at least for one copy. It wouldn't make any sense to say "Leave the dictionary open to "ibex" and open the dictionary to "hyrax". You have to have some unique way of referring to each copy, such as "Leave the dictionary on my left open to "ibex" and open the dictionary on my right to "hyrax"."

Multiple clob fields in a single table

Are there any known performance issues associated with having 4 CLOB fields in a single table... the table as such will be relatively small.. like 100 MB... with most rows being << 50k.

Not really. If you need 4 CLOB columns and it makes sense to have alll the columns in a single table, go for it.
Justin
Distributed Database Consulting, Inc.
http://www.ddbcinc.com/askDDBC

How to restore a single table from a DP Export from a different schema?

Environment:
Oracle 11.2.0.3 EE on Solaris
I was looking at the documentation on DP Import trying to find the correct syntax to import a single table from a DP Export of a different schema.
So, I want to load table USER1.TABLE1 into USER2.TABLE1 from a DP Export.
Looking at the REMAP_TABLE options:
REMAP_TABLE=[schema.]old_tablename[.partition]:new_tablename
OR
REMAP_TABLE=[schema.]old_tablename[:partition]:new_tablenameI can't see where to specify the target schema name. The examples had the new table name residing in the same schema with just a new name.
I looked at the REMAP_SCHEMA but the docs say that will import the entire schema into the new schema and I only want one (1) table.
Any suggestions are most welcome!
-gary

I thought I tried that combination and it seemed to me that the REMAP_SCHEMA somehow over-rode the TABLES= parameter >and started loading all the objects.If it does fail (and it should not) then please post the details here and I will try to see what is happening.
Let me get back into the sandbox and try it again. I admit I was in a bit of a hurry when I did it the first time.We are all in a hurry, no worries. If it fails, please post the details and the log file.
Does it make any sense that one parameter would override another?No, this should never happen. We have tons of checks to make sure the job can't have multiple meanings. For example, you can't say
full=y schemas=foo --- Which do you want, a full export or a list of schema exports, etc.
Your suggestion was the first thing I thought would work.This should work. If not, please post the log file with the command and the results.
Dean
Thanks again for the help and stay tuned for my new attempt.
-gary

Two Fields in a Single Table

Hello All,
I'm a newbie to the forum & to Crystal(9), I've searched the forum and ca't exactly find an answer to my question:
My goal is to be able to pull the Company Member Type & the Contact Member Type as part of the same report in the selection criteria.
My problem is: They both reside in the same table...
The question is: "how to be able to pull the info?"
If I need to provide more or clearer info pleasde let me know. Any help is appreciated.
Lost in DC - DJ

If you have a single table datasource record duplication wouldn't be a result of the select expert. In fact, I can't think of a case where a single table datasource could possibly duplicate records.
The duplicates must be the result of a join.
To answer your initial question, the select expert you enter is subjected, in its entirety, to each record in the joined tables.
The problem that I see with the above suggestion relates to precedence.
This:
cond 1 AND cond 2 AND cond 3 OR cond 4
Is not this:
cond 1 AND cond 2 AND (cond 3 OR cond 4)
In the case of the non-paren-ed select statement, it will return records that satisfy ALL of the AND conditions OR just the or condition.
In the second case, it will return all records that satisfy condition 1 and condition 2 AND either condition 3 or condition 4.
Try bracketing the ored conditions from the same table. That should solve your select problem, but not the duplication problem.

Recover a single table using RMAN

Hi,
I'm working on an Oracle Database 11g Release 11.1.0.6.0 - 64bit Production With the Real Application Clusters option.
I did a bad update on a table.
I have a full backup level 0 before the update
Is it possibile to recover the single table in an instant before the update using RMAN?
Thanks in advance.
Samuel

Hi Samuel,
How long ago was the update committed? What's the value of undo_retention?
If the undo has not yet expired, the easiest way to recovery is through flashback query. (Note that flashback database does not have to be enabled for flashback query to work.)
See MOS Doc ID 238674.1.
If that's not a possibility, and flashback database is not enabled, the only other option is to do an out-of-place restore, of SYSTEM, UNDO, and tablespace containing the table you want to recover, and recover to point in time before the update. Then, export table, drop the database, and import table into your primary database.
Hope that helps,
-Mark

How will check the space taken by a single table in a tablespace ?

How will check the space taken by a single table in a tablespace ?
dba_segments is giving the same values even if I truncate the table?
Pls reply

I need to know how can we find out the size of the table in the tablespace.use user_segments (bytes) column.
How much bytes it has taken ?value from user_segments, bytes column
If u delete records will the space be used for another table in same tablespace?No, it keep the space in the same table for future usage.
How can we free that space ?truncate or drop the table and reduce the size from tablespace, if you want to reclaim the space from the tablespace, OS level.
Jaffar

Adding a single table without a logical join to another table (OBIEE 10g)

Sometimes I want to just display a single table without a logical join to another table in the repository. However, everytime I move it to the Business Model and Mapping layer and perform a Global Consistency Check, it tells me that it needs a logical join and I am forced to create another table to join to it. Thus creating a dimension-fact relationship. There are times I don't need this relationship and just want to display some data. Is there anyway to get around this?
Thanks in advance!

Yes,You have to create a join.You cannot take single table to BMM layer.You can create an alias of the table.Join this alias and base table through any common column and take both tables to BMM and desired table to presentation layer.
Another way is to create a view in physcial layer.Write a select statement like
Select primary_key from Table
Where primary_key is primary key of base table.Join this view ith base table and repeat the steps defined for Alias.
Regards,
Sandeep

How to get the data from multiple tabes into single table

hi all,
here i am having 10 data base tables,how to get the data into a single table.
regards,
subba reddy

hi,
non XI/PI related
Regards,
Michal Krawczyk

Creation of view on single table?

Hi Team,
I have a requirement like for creaation of view on single table (QMEL) in SAP ECC side...
Note: in this table i need 2o fields only....not all fields.
First can we create view on single table?
if 'Yes' can any one tell , How we can creat view on single table?
While creation of view we have four options..
1)Data base view
2)Projection View
3)Maintanace view
4)Help view
in these four options which tyep of view we can choose for creation?
please can any one suggest me and do the need full..
i am waiting your responce...

I quickly skimmed the links provided by others; and in my short discussions with DBA friend of mine; and other sources... partition should be based on user needs, sql server resources, and partition maintenance time.
Lets say you have 50 regions and 1) partition the data by region, AND 2) place each partition on a different disk, and 3) i am in Texas and only query data in the Texas region then performance will be increased because I am not scanning through the other
49 regions.
If you have temporal data (dependent on time - like say financial reports that are sent to the SEC) - the partitions are by time: 1) data from last 13 months is stored on SSD, 2) data 13 months - 3 years old is on HDD, and 3) data >3 years old is stored
on compressed HDD. (i say 13 months so you have an entire year and month to date) --- accountants can get the current data VERY quickly, project managers who need to see a 3 year trend will not have to wait long, and when the SEC calls, who cares?,
the reports can be queued and generated at night when no one is working.
I see partitions are giving the users the least amount of data to query which speeds their results.

Single table hash clusters

I created a single table hash cluster like this :
create tablespace mssm datafile 'c:\app\mssm01.dbf' size 100m
segment space management manual;
create cluster hash_cluster_4k
( id number(2) )
size 8192 single table hash is id hashkeys 4 tablespace mssm;
-- Created a table in cluster with row size such that only one record fits one block and inserted 5 records each with a distinct key value
CREATE TABLE hash_cluster_tab_8k
( id number(2) ,
txt1 char(2000),
txt2 char(2000),
txt3 char(2000)
CLUSTER hash_cluster_8k( id );
Begin
for i in 1..5 loop
insert into hash_cluster_tab_8k values (i, 'x', 'x', 'x');
end loop;
end;
exec dbms_stats.gather_table_stats(USER, 'HASH_CLUSTER_TAB_8K', CASCADE=>true);
Now, If I try to access record with id = 1 - It shows 2 I/O's (cr = 2) instead of single I/O as is expected in a hash cluster.
Rows Row Source Operation
1 TABLE ACCESS HASH HASH_CLUSTER_TAB_8K (cr=2 pr=0 pw=0 time=0 us)
If I issue the same query after creating unique index on hash_cluster_tab(id), the execution plan shows hash access and single I/O (cr = 1).
Does it mean that to have single I/o in a single table hash cluster, we have to create unique index? Won't it create additional overhead of maintaining an index?
What is the second I/O needed for in case unique index is absent?
I would be extremely thankful if gurus could explain this behaviour .
Thanks in advance ..

>
Now, If I try to access record with id = 1 - It shows 2 I/O's (cr = 2) instead of single I/O as is expected in a hash cluster.
1 TABLE ACCESS HASH HASH_CLUSTER_TAB_8K (cr=2 pr=0 pw=0 time=0 us)
>
As expected? Have you considered that your 'expectation' is wrong?
>
If I issue the same query after creating unique index on hash_cluster_tab(id), the execution plan shows hash access and single I/O (cr = 1).
Does it mean that to have single I/o in a single table hash cluster, we have to create unique index? Won't it create additional overhead of maintaining an index?
What is the second I/O needed for in case unique index is absent?
>
My hypothesis would be that are seeing the effects of having a 'hash collision'; a collision that you caused yourself by the way you defined the table.
Remember when you said this?
>
create cluster hash_cluster_4k
( id number(2) )
size 8192 single table hash is id hashkeys 4 tablespace mssm;
>
You told Oracle there will only be FOUR different IDs used.
And then you said this
>
-- Created a table in cluster with row size such that only one record fits one block and inserted 5 records each with a distinct key value
>
You used FIVE different IDs and only ONE record will fit into each block.
So that record with 'ID=5' is guaranteed to HASH to one of the existing four hash values. And that means you have a 'hash collision'.
The docs explain what happens when you have a 'hash collision'. See the 'Hash Cluster Storage' section in the Database Concepts doc
http://docs.oracle.com/cd/E11882_01/server.112/e25789/tablecls.htm#sthref258
>
Hash Cluster Storage
Oracle Database allocates space for a hash cluster differently from an indexed cluster. In Example 2-9, HASHKEYS specifies the number of departments likely to exist, whereas SIZE specifies the size of the data associated with each department. The database computes a storage space value based on the following formula:
HASHKEYS * SIZE / database_block_size
Thus, if the block size is 4096 bytes in Example 2-9, then the database allocates at least 200 blocks to the hash cluster.
Oracle Database does not limit the number of hash key values that you can insert into the cluster. For example, even though HASHKEYS is 100, nothing prevents you from inserting 200 unique departments in the departments table. However, the efficiency of the hash cluster retrieval diminishes when the number of hash values exceeds the number of hash keys.
>
Using that formula above with HASHKEYS=4, SIZE=8192 and block size=8192 Oracle allocates at least 4 blocks.
The next two paragraphs tell you what happens for a use case like yours: HASH COLLISION
>
To illustrate the retrieval issues, assume that block 100 in Figure 2-7 is completely full with rows for department 20. A user inserts a new department with department_id 43 into the departments table. The number of departments exceeds the HASHKEYS value, so the database hashes department_id 43 to hash value 77, which is the same hash value used for department_id 20. Hashing multiple input values to the same output value is called a hash collision.
When users insert rows into the cluster for department 43, the database cannot store these rows in block 100, which is full. The database links block 100 to a new overflow block, say block 200, and stores the inserted rows in the new block. Both block 100 and 200 are now eligible to store data for either department. As shown in Figure 2-8, a query of either department 20 or 43 now requires two I/Os to retrieve the data: block 100 and its associated block 200. You can solve this problem by re-creating the cluster with a different HASHKEYS value.
>
Note the next to last sentence:
>
As shown in Figure 2-8, a query of either department 20 or 43 now requires two I/Os to retrieve the data: block 100 and its associated block 200.
>
Hmmmm - sounds suspiciously like your use case don't you think?
Try what the doc says in that last sentence and see if it solves your problem:
>
You can solve this problem by re-creating the cluster with a different HASHKEYS value.
>
The parameters you provided and the table example you are using GUARANTEE that if more than FOUR ids are used there will be hash collisions and the result MUST BE what the doc describes. There will NEVER be space in an existing block for a second row so a new block has to be used and that means 'chaining' the blocks to find the one you need: one I/O for each block in the chain.
Jonathan said he could not reproduce your problem but the 'hash' algorithm for his instance might have hashed 'ID=5' to a different value; his 'hash collision' might only occur for ID=2 (or 3 or 4).

How to combine large number of key-value pair tables into a single table?

I have 250+ key-value pair tables with the following characteristics
1) keys are unique within a table but may or may not be unique across tables
2) each table has about 2 million rows
What is the best way to create a single table with all the unique key-values from all these tables? The following two queries work till about 150+ tables
with
t1 as ( select 1 as key, 'a1' as val from dual union all
          select 2 as key, 'a1' as val from dual union all
          select 3 as key, 'a2' as val from dual )
, t2 as ( select 2 as key, 'b1' as val from dual union all
          select 3 as key, 'b2' as val from dual union all
          select 4 as key, 'b3' as val from dual )
, t3 as ( select 1 as key, 'c1' as val from dual union all
          select 3 as key, 'c1' as val from dual union all
          select 5 as key, 'c2' as val from dual )
select coalesce(t1.key, t2.key, t3.key) as key
,      max(t1.val) as val1
,      max(t2.val) as val2
,      max(t3.val) as val3
from t1
full join t2 on ( t1.key = t2.key )
full join t3 on ( t2.key = t3.key )
group by coalesce(t1.key, t2.key, t3.key)
with
master as ( select rownum as key from dual connect by level <= 5 )
, t1 as ( select 1 as key, 'a1' as val from dual union all
          select 2 as key, 'a1' as val from dual union all
          select 3 as key, 'a2' as val from dual )
, t2 as ( select 2 as key, 'b1' as val from dual union all
          select 3 as key, 'b2' as val from dual union all
          select 4 as key, 'b3' as val from dual )
, t3 as ( select 1 as key, 'c1' as val from dual union all
          select 3 as key, 'c1' as val from dual union all
          select 5 as key, 'c2' as val from dual )
select m.key as key
,      t1.val as val1
,      t2.val as val2
,      t3.val as val3
from master m
left join t1 on ( t1.key = m.key )
left join t2 on ( t2.key = m.key )
left join t3 on ( t3.key = m.key )
/

A couple of questions, then a possible solution.
Why on earth do you have 250+ key-value pair tables?
Why on earth do you want to consolodate them into one table with one row per key?
You could do a pivot of all of the tables, without joining. something like:
with
t1 as ( select 1 as key, 'a1' as val from dual union all
          select 2 as key, 'a1' as val from dual union all
          select 3 as key, 'a2' as val from dual )
, t2 as ( select 2 as key, 'b1' as val from dual union all
          select 3 as key, 'b2' as val from dual union all
          select 4 as key, 'b3' as val from dual )
, t3 as ( select 1 as key, 'c1' as val from dual union all
          select 3 as key, 'c1' as val from dual union all
          select 5 as key, 'c2' as val from dual )
select key, max(t1val), max(t2val), max(t3val)
FROM (select key, val t1val, null t2val, null t3val
      from t1
      union all
      select key, null, val, null
      from t2
      union all
      select key, null, null, val
      from t3)
group by keyIf you can do this in a single query, unioning all 250+ tables, then you do not need to worry about chaining or migration. It might be necessary to do it in a couple of passes, depending on the resources available on your server. If so, I would be inclined to create the table first, with a larger than normal percent free, then do the first set as a straight insert, and the remaining pass or passes as a merge.
Another alternative might be to use the approach above, but limit the range of keys in each pass. So pass one would have a predicate like where key between 1 and 10 in each branch of the union, pass 2 would have key between 11 and 20 etc. That way everything would be straight inserts.
Having said all that, I go back to my second question above, why on earth do you want/need to do this? What is the business requirement you are trying to solve. There might be a much better way to meet the requirement.
John

Single table growth

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