Gathering statistics on interMedia indexes and tables

Has anyone found any differences (like which one is better or worse) between using the ANALYZE sql command, dbms_utility package, or dbms_stats package to compute or estimate statistics for interMedia text indexes and tables for 8.1.6? I've read the documentation on the subject, but it is still unclear as to which method should be used. The interMedia text docs say the ANALYZE command should be used, and the dbms_stats docs say that dbms_stats should be used.
Any help or past experience will be grateful.
Thanks,
jj

According to the Support Document "Using statistics with Oracle Text" (Doc ID 139979.1), no:
Q. Should we gather statistics on the underlying DR$/DR# tables? If yes/no, why?
A. The recommendation is NO. All internal recursive queries have hints to fix the plans that are deemed most optimal. We have seen in the past that statistics on the underlying DR$ tables may cause query plan changes leading to serious query performance problems.
Q. Should we gather statistics on Text domain indexes ( in our example above, BOOKS_INDEX)? Does it have any effect?
A: As documented in the reference manual, gathering statistics on Text domain index will help CBO to estimate selectivity and costs for processing a CONTAINS() predicate. If the Text index does not have statistics collected, default selectivity and cost will be used.
So 'No' on the DR$ tables and indexes, 'yes' on the user table being indexed.

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InterMedia indexing and searching of zipped files

Hello, I have interMedia successfully configured to index and query a repository of files (MS Word, Excel, PPT, PDFs, txt files)which are located on a file system. My issue is with zip files. I cannot successfully index and search zip files. I've tried zips that contain both ascii(text) and formatted files (doc, ppt), but interMedia seems not to recognize this particular MIME type. Is there a way to have interMedia index and search zip files? Thanks in advance for any assistance.

You will have more luck with this question if you post it in the Oracle Text forum. This forum is for interMedia (image, audio video).

Question about Global index and Table Partitions

I have created a global index for a partitioned table now in the future the partitions will be dropped in the table. Do I need to do anything to the global index? Does it need to be rebuilt or would it be ok if partitions get dropped in the table?

>
I have created a global index for a partitioned table now in the future the partitions will be dropped in the table. Do I need to do anything to the global index? Does it need to be rebuilt or would it be ok if partitions get dropped in the table?
>
You can use the UPDATE INDEXES clause. That allows users to keep using the table and Oracle will keep the global indexes updated.
Otherwise, as already stated all global indexes will be marked UNUSABLE.
See 'Dropping Partitions' in the VLDB and Partitioning Guide
http://docs.oracle.com/cd/E11882_01/server.112/e25523/part_admin002.htm#i1007479
>
If local indexes are defined for the table, then this statement also drops the matching partition or subpartitions from the local index. All global indexes, or all partitions of partitioned global indexes, are marked UNUSABLE unless either of the following is true:
You specify UPDATE INDEXES (Cannot be specified for index-organized tables. Use UPDATE GLOBAL INDEXES instead.)
The partition being dropped or its subpartitions are empty

Using large block sizes for index and table spaces

" You are not using large blocksizes for your index tablespaces. Oracle research proves that indexes will build flatter tree structures in larger blocksizes.
Is this a generic statement that I can use for all tables or indexes? I also have batch and online activity. My primary target is batch and it should not impact online. Not sure if both have common tables.
How to find the current block size used for tables and index? is there a v$parameter query?
What is an optimal block size value for batch?
How do I know when flatter tree str has been achieved using above changes? Is there a query to determine this?
What about tables, what is the success criterion for tables. can we use the same flat tree str criterion? Is there a query for this?

user3390467 wrote:
" You are not using large blocksizes for your index tablespaces. Oracle research proves that indexes will build flatter tree structures in larger blocksizes.
Is this a generic statement that I can use for all tables or indexes? This is a generic statement used by some consultants. Unfortunately, it is riddled with exceptions and other considerations.
One consultant in particular seems to have anecdotal evidence that using different block sizes for index (big) and data (small) can yield almost miraculous improvements. However, that can not be backed up due to NDA. Many of the rest of us can not duplicate the improvements, and indeed some find situations where that results in a degradation (esp with high insert/update rates from separated transactions).
I also have batch and online activity. My primary target is batch and it should not impact online. Not sure if both have common tables.
How to find the current block size used for tables and index? is there a v$parameter query?
What is an optimal block size value for batch?
How do I know when flatter tree str has been achieved using above changes? Is there a query to determine this?
What about tables, what is the success criterion for tables. can we use the same flat tree str criterion? Is there a query for this?I'd strongly recommend that you
1) stop using generic tools to analyze specific problems
2) define you problem in detail ()what are you really trying to accomplish - seems like performance tuning, but you never really state that)
3) define the OS and DB version - in detail. Give rev levels and patch levels.
If you are having a serious performance issue, I strongly recommend you look at some performance tuning specialists like "http://www.method-r.com/", "http://www.miracleas.dk/", "http://www.hotsos.com/", "http://www.pythian.com/", or even Oracle's Performance Tuning consultants. Definitely worth the price of admission.

Index and statistics

for infoprovider, what is the problem to run the indicex, but not statistics them?

Statistics tell the optimizer things like how many values there, how similar or unique the values are, etc. The database optimizer uses the index and table statistics to make decisions about how best to execute the query, e.g. perform indexed reads of the table or a full table scan, or what order to read tables. The CBO (Cost Based Optimzer) is generally trying to find the execution plan that requires the fewest system resources, generally the fewest IOs (but there are other factors in the mix). It may examine hundreds or thousands of different execution plans to find wht it thinks is best.
Without any / good statistics the CBO may make bad choices about how to execute the query, that are not the most efficient.
When you drop and rebuild the indices, you lose the statistics which could easily result in bad choices by the CBO (Cost Based Optimizer).

Percent Gathering Statistics with FND_STATS

Hi,
We gather statistics for the schemas and tables in our database using the FND_STATS package. Now we are running it with an 80% sample. Once we run it at 30 % and we had a lot of performance issues.
How can we determine the optimal value for percentage?
What percentage is usually used for E-Business suite?
Thanks in advance for your help.
Carlos

How Often Should Gather Schema Statistics Program be Run?
There is no set schedule for gathering schema statistics. On some systems the program should be run weekly. On other systems once per month will be often enough. The schedule will vary greatly depending on the amount and nature of the data and how often the data changes.
It will be necessary to try different schedules over time and monitor performance to determine the most effective schedule.
As a general rule, run Gather Schema Statistics under the following circumstances:
1. After there has been a significant change in data in either content or volume
2. After importing data
3. Any time end-users notice a deterioration in performance in routine day-to-day business transactions or when running concurrent programs

Index Vs table partition

I have table whose growth is 1 million per month and may increase in future. I currently place an index on column which is frequently uses in where clause. there is another column which contains months so it may possible that I make 12 partitions of that. I want to know what is suitable. is there any connection between index and table partition?
Message was edited by:
user459835

I think the question is more of what type of queries are answered by this table?
is it that most of the times the results returned span across several months?
is there any relation to the column you use in where clause with the data belonging to a particular month (or range there-of)?

Updating interMedia Index

Hi,
I need to know if there's an aitomated way of updating the interMedia index in Portal 3.0.9 (other than dropping the index and re-creating it from the UI). Is there any in-built program for performing the same action.
Thanks in advance.
Regards,
Jatinder

When you have created your Portal intermedia indexes and add a file item, this is not indexed automatically. You
cannot yet search on it. You have to recreate the Portal intermedia indexes, or you can schedule to synchronize
them.
You can download the file ctx_schedule from technet.
Step for automatic synchronization:
1. Install the package ctx_schedule (ctx_schedule.sql) in schema ctxsys.
2. Schedule to synchronize the Portal intermedia indexes every minute, and optimize them every 120 minutes.
Run script START_PORTAL_INDEX_REFRESH.SQL in ctxsys schema.
To stop the automatic synchronization run script STOP_PORTAL_INDEX_REFRESH.SQL.

Importing a table and its index statistics, cannot import index stats

Hi,
Oracle 10.2.0.4 on Solaris.
I have DBA to imprt tables and index statistics for a table from prod into QA for further analysis. The stats for this table are locked in prod
DBA has used the following command for export and import table statistics
exec dbms_stats.export_table_stats('SCHEMA','TABLE',null,'TABLE_20130225',null,true,'INV');
exec dbms_stats.import_table_stats('SCHEMA','TABLE',null,'TABLE_20130225',null,true,'SCHEMA');Although cascade is set to true above, this resulted in "only table stats" to be imported no index stats. So we have imported the prod table level stats but no index stats! FYI, the indexes in prod have stats (last_analyzed) set.
Next DBA tried the export and import using export_index_stats and import_index_stats but no luck. DBA advising me that the only option we have is to import the table itself from prod to QA. It seems that import with cascade does not work.
Is this a bug in 10g or there is another way around to get index statistics as well?
Thanks
Edited by: 902986 on 25-Feb-2013 06:22

902986 wrote:
Hi,
Oracle 10.2.0.4 on Solaris.
I have DBA to imprt tables and index statistics for a table from prod into QA for further analysis. The stats for this table are locked in prod
DBA has used the following command for export and import table statistics
exec dbms_stats.export_table_stats('SCHEMA','TABLE',null,'TABLE_20130225',null,true,'INV');
exec dbms_stats.import_table_stats('SCHEMA','TABLE',null,'TABLE_20130225',null,true,'SCHEMA');Although cascade is set to true above, this resulted in "only table stats" to be imported no index stats. Problem Exists Between Keyboard And Chair
"Gather statistics on the indexes for this table. Index statistics gathering is not parallelized. Using this option is equivalent to running the GATHER_INDEX_STATS Procedure on each of the table's indexes. Use the constant DBMS_STATS.AUTO_CASCADE to have Oracle determine whether index statistics to be collected or not. This is the default. The default value can be changed using theSET_PARAM Procedure."
Handle:     902986
Status Level:     Newbie
Registered:     Dec 17, 2011
Total Posts:     69
Total Questions:     18 (12 unresolved)
Why so MANY unanswered questions?

Gathering statistics on partitioned and non-partitioned tables

Hi all,
My DB is 11.1
I find that gathering statistics on partitioned tables are really slow.
TABLE_NAME                       NUM_ROWS     BLOCKS SAMPLE_SIZE LAST_ANALYZED PARTITIONED COMPRESSION
O_FCT_BP1                        112123170     843140    11212317 8/30/2011 3:5            NO                    DISABLED
LEON_123456                      112096060     521984    11209606 8/30/2011 4:2           NO                   ENABLED
O_FCT                           115170000     486556      115170 8/29/2011 6:3            YES
SQL> SELECT COUNT(*) FROM user_tab_subpartitions
2 WHERE table_name =O_FCT'
3 ;
COUNT(*)
       112I used the following script:
BEGIN
DBMS_STATS.GATHER_TABLE_STATS(ownname          => user,
                                tabname          => O_FCT',
                                method_opt       => 'for all columns size auto',
                                degree           => 4,
                                estimate_percent =>10,
                                granularity      => 'ALL',
                                cascade          => false);
END;
/It costs 2 mins for the first two tables to gather the statistics respectively, but more than 10 mins for the partitioned table.
The time of collecting statistics accounts for a large part of total batch time.
And most jobs of the batch are full load in which case all partitions and subpartitions will be affected and we can't just gather specified partitions.
Does anyone have some experiences on this subject? Thank you very much.
Best regards,
Leon
Edited by: user12064076 on Aug 30, 2011 1:45 AM

Hi Leon
Why don't you gather stats at partition level? If your partitions data is not going to change after a day (date range partition for ex), you can simply do at partition level
GRANULARITY=>'PARTITION' for partition level and
GRANULARITY=>'SUBPARTITION' for subpartition level
You are gathering global stats every time which you may not require.
Edited by: user12035575 on 30-Aug-2011 01:50

EAR4 - Gathering Statistics, unusable indexes and more

Hi,
Some feedback on statistics:
1. When choosing a table -> Statistics -> gather Statistics, the minimum is to have a CASCADE option (so all the indexes will be analyzed too). I think it should be the deafult! This way there is a chance that the developers will have good statistics...
As a bonus, an advanced tab with the rest of the options might be nice, when you have time.
2. When choosing to gather statistics on an index, you should you dbms_stats and not ALTER INDEX... COMPUTE STATISTICS which is a deprecated syntax.
And about indexes:
1. When looking at the index tab of a table, unusable indexes should be visibly different - maybe just color the status column. Well, any color-coding can help to gain more infomation very fast (index types and index status). Well, I guess the same goes for disabled triggers, disabled constraints etc...
2. When right-clicking an index in an index tab of a table, the only option is export, which makes no sense. Could you replace it with the six relevant index options, just like when we right click an index in the side bar (drop, rebuild, rename, make unusable...)
Well, same goes for the triggers tab of a table - when right-clicking a trigger give us the trigger actions(enable/disable, drop...), not export.
my two cents,
Ofir

When Choose a partitioned table from the tables list (tree view on the left), I have many tabs with details (Columns, data, indexes,etc).
1. The last tab, SQL, doesn't generate any CREATE TABLE sql at all for the simple partition table I created (10g Release 2 on windows 2000, raptor 4.1, a table with a single partition).
2. There is no way to see the partitions definitions - for example, the list of partitions and their ranges (or list values). I would like to have another tab for partitioned table with that information (from all_tab_partitions). Also, how can I easily see the type of partitioning and the partition key of the table?
3. Also in the builtin reports, there is no way to get that data. The only report about partitioned tables that I see is Table -> Organization -> Partitioned -> Partitioned Tables, that only provide owner, table_name, maybe tablespace and logging (blank in my case).. I think:
a. You should rewrite the report to use dba/all_part_tables - with columns like partitioning_type, subpartitioning_type, partition_count etc.
b. add a report about the partition key columns per partitioned table from dba_part_key_columns.
4. When adding an index to a partitioned table, I can't choose local/global index. The index is always created as a global index. For example, can't create bitmap index on partitioned tables because they must be local.
Ofir

Performance Problems - Index and Statistics

Dear Gurus,
I am having problems lossing indexes and statistics on cubes ,it seems my indexes are too old which in fact are not too old just created a month back and we check indexes daily and it returns us RED on the manage TAB.
please help

Dear Mr Syed ,
Solution steps I mentioned in my previous reply itself explains so called RE-ORG of tables;however to clarify more on that issue.
Occasionally,ORACLE Cost-Based Optimizer may calculate the estimated costs for a Full Table Scan lower than those for an Index Scan, although the actual runtime of an access via an index would be considerably lower than the runtime of the Full Table Scan,Some Imperative points to be considered in order to perk up the performance and improve on quandary areas such as extensive running times for Change runs & Aggregate activate & fill ups.
Performance problems based on a wrong optimizer decision would show that there is something serious missing at Database level and we need to RE_ORG the degenerated indexes in order to perk up the overall performance and avoid daily manual (RSRV+RSNAORA)activities on almost similar indexes.
For Re-organizing degenerated indexes 3 options are available-
1) DROP INDEX ..., and CREATE INDEX 
2)ALTER INDEX <index name> REBUILD (ONLINE PARALLEL x NOLOGGING)
3) ALTER INDEX <index name> COALESCE [as of Oracle 8i (8.1) only]
Each option has its Pros & Cons ,option 2 seems to be having lot of advantages to
Advantages- option 2
1)Fast storage in a different table space possible
2)Creates a new index tree
3)Gives the option to change storage parameters without deleting the index
4)As of Oracle 8i (8.1), you can avoid a lock on the table by specifying the ONLINE option. In this case, Oracle waits until the resource has been released, and then starts the rebuild. The "resource busy" error no longer occurs.
I would still leave the Database tech team be the best to judge and take a call on these.
These modus operandi could be institutionalized for all fretful cubes & its indexes as well.
However,I leave the thoughts with you.
Hope it Helps
Chetan
@CP..

Which Event Classes i should use for finding good indexs and statistics for queries in SP.

Dear all,
I am trying to use pro filer to create a trace,so that it can be used as workload in
"Database Engine Tuning Advisor" for optimization of one stored procedure.
Please tel me about the Event classes which i should use in trace.
The stored proc contains three insert queries which insert data into a table variable,
Finally a select query is used on same table variable with one union of the same table variable, to generate a sequence for records based on certain condition of few columns.
There are three cases where i am using the above structure of the SP, so there are three SPS out of three , i will chose one based on their performance.
1) There is only one table with three inserts which gets into a table variable with a final sequence creation block.
2) There are 15 tables with 45 inserts , which gets into a tabel variable with a final
sequence creation block.
3)
There are 3 tables with 9 inserts , which gets into a table variable with a final
sequence creation block.
In all the above case number of record will be around 5 lacks.
Purpose is optimization of queries in SP
like which Event Classes i should use for finding good indexs and statistics for queries in SP.
yours sincerely

"Database Engine Tuning Advisor" for optimization of one stored procedure.
Please tel me about the Event classes which i should use in trace.
You can use the "Tuning" template to capture the workload to a trace file that can be used by the DETA. See
http://technet.microsoft.com/en-us/library/ms190957(v=sql.105).aspx
If you are capturing the workload of a production server, I suggest you not do that directly from Profiler as that can impact server performance. Instead, start/stop the Profiler Tuning template against a test server and then script the trace
definition (File-->Export-->Script Trace Definition). You can then customize the script (e.g. file name) and run the script against the prod server to capture the workload to the specified file. Stop and remove the trace after the workload
is captured with sp_trace_setstatus:
DECLARE @TraceID int = <trace id returned by the trace create script>
EXEC sp_trace_setstatus @TraceID, 0; --stop trace
EXEC sp_trace_setstatus @TraceID, 2; --remove trace definition
Dan Guzman, SQL Server MVP, http://www.dbdelta.com

Relation between computing and gathering statistics

Hi gurus,
What is the relation between computing and gathering statistics for a database object.Are they mutually dependent or one doesn't have anything to do with the other?How they affect performance of a database??
plz dont redirect..just bottom lines are expected(be specific)
Thanks in advance
anirban

computing term used to collect 100% statistics along with analyze command.
gather stats is a new package provided by the oracle, also recommend to use this instead of analyze. You can also take 100% stats, like compute with analyze command, in gather stats pacakge, parameter estimate_percent=>null.
exec dbms_stats.gather_table_stats('SCHEMA',TABLE',cascade=>true,estimate_percent=>NULL);
Jaffar

What happens to Existing index after table partition and created with local index

Hi guys,
desc part id number, name varchar2(100), salary number
In an existing table PART i am adding 1 more column DATASEQ NUMBER. i am asked to partition the table part based on dataseq.now the table is created with this logic
create table part( id number, name varchar2(100), salary number, DATASEQ number) partition by list(dataseq) (partition PART_INITIAL values (1));
Suggestionn required. since the table is partitioned based on DATASEQ i am asked to add local index on dataseq. i have added local index to dataseq create index idx on part(dataseq) LOCAL; Now my question is already there is existing index is for the column ID and salary.
1) IDX for dataseq is created locally so that it will have partition on each partition on the main table. Please tell me what happens to the existing index on the column ID and salary.. will it again created in local?
Please suggest
S

Hi,
first of all, in reality "partition a table" means create a new table a migrate existing data there (although theoretically you can use dbms_redefinition to partition an existing table -- however, it's just doing the same thing behind the scenes). This means that you also get to decide what to do with the indexes -- which indexes will be local, which will be global (you can also re-evaluate some of existing indexes and decide that they're not really needed).
Second of all, the choice of partitioning key looks odd. Partitioning is a data manageability technique more than anything else, so in order to benefit from it you need to find a good partitioning key. A recently added column named "data_seq" doesn't look like a good candidate. Can you provide more details about this column and why it was chosen as a partitioning key?
I suspect that whoever suggested this partitioning scheme is making a huge mistake. A non-partitioned table is much better in all aspects (including manageability and performance) than wrongly partitioned one.
Best regards,
Nikolay

Gathering statistics on interMedia indexes and tables

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