flodubois 270000K6H5 Visits (1191)
Q. If PIECESIZE is specified at maximum of 64GB and (LARGE or DSSIZE x is specified on tablespace), then is the maximum pageset size going to be 64GB*4096 parts =256TB?
A. The number of index data sets is influenced by the number of data partitions. Initially using PIECESIZE of 64GB you could not index 128TB of data using DSSIZE 128 GB or 256 GB due to the reduced number of index data sets. APAR PM42175 was created to allow the specification of 128 GB and 256 GB PIECESIZE.
Specification of 64GB is only allowed when the number of data partitions (derived from DSSIZE) is less than the following maximum data parts.
Chart for 128GB PIECESIZE
Chart for 256GB PIECESIZE
Q. Now that DB2 can support a DSSIZE of 256GB for tablespace what is the new max size for the NPI?
Q. Is the only way to influence it - by increasing DSSIZE for the tablespace?
Q. Is there a way to calculate how much is space is actual used/left to grow based on the Catalog or RTS?
flodubois 270000K6H5 Visits (1511)
Migrating an SQL stored procedure from external to native is not as simple as a DROP/CREATE. You need to understand the release incompatibilities related to SQL stored procedures, examine your external SQL procedure source code, and make any necessary adjustments. This APAR can help you do that. It provides sample job DSNTEJ67 which initiates the process of converting source for an external SQL procedure into source for a native SQL procedure. REXX services, native SQL PL and the HOST(SQLPL) checkout precompiler are combined to extract, inspect, analyze and convert external SQL procedure source code. The appropriate set of native SQL procedure options are applied and a listing of the modified SQL procedure source code is produced.
flodubois 270000K6H5 Visits (1419)
New Site (same URL)
(you will need an IBM ID in order to join the developerWorks community)
The DB2 for z/OS Best Practices web page has moved to a developerWorks community. This move brings with it the following features:
* Video content is streamed from YouTube with HD quality possible.
* From YouTube you can download video to your disk.
* The site allows you to comment on individual Best Practices.
* You can still download transcripts and slides of presentations from the site.
* Content is still organized using the DB2 Roadmap with tags for each category
* Feeds and Social Media integration provided by developerWorks communities.
The one-day seminar "Recommendations from DB2 Health Check Studies" by John Campbell and Florence Dubois has been recorded in 4 parts:
* Continuous Availability
* Special Considerations for WLM, CICS, and DDF
* Speed of Recovery
A popular presentation on writing SQL for improved performance is presented by Tom Beavin:
* SQL Performance (Part 1 & 2)
Best practices for achieving stability in your DB2 access paths is presented by Tom Beavin:
* Achieving Access Path Stability (Part 1 & 2)
Michael_D. 1100004WAH Visits (1010)
Michael_D. 1100004WAH Visits (1186)
Michael_D. 1100004WAH Visits (1151)
HELP WITH HANDLING THE RELEASE INCOMPATIBLE CHANGE FOR VARCHAR( DECIMAL), CAST (DECIMAL AS CHAR), CAST(DECIMAL AS VARCHAR)
Michael_D. 1100004WAH Visits (8904)
In Version 10, the formatting of decimal data has changed for the VARCHAR function and the CAST specification with decimal input and VARCHAR or CHAR output. There are two changes:
- Remove leading zero
Michael_D. 1100004WAH Visits (1225)
agburke 060001QPDN Visits (1424)
I wanted to remind everyone that there is a very comprehensive website in developerworks that lists best practices for many topics from LOBs, to Utilities, to stored procedures.
The content includes downloadable presentations as well as pre-recorded webcasts so that you can walk through the slides as the moderator is presenting.
Here is the URL and a screen shot of the Monitoring and Tuning port
agburke 060001QPDN Visits (1261)
As many of you know IBM has changed the products that come in the DB2 Accessories Suite.
At one point we had the DB2 Management Clients Package which contained Visual Explain and Control Center, and anything that would be installed on your desktop.
Starting in DB2 9 for z/OS we changed it to the DB2 Accessories Suite which included things like Optimization Service Center, OmniFind Text search, and Spatial Support. Within that same release we deprecated OSC, and with DB2 10 for z/OS the Accessories Suite included only the spatial support and international Unicode support (ICU).
The link below breaks down which products appear in which release of the Accessories Suite, and relates it to the appropriate release of DB2.
URL for II14
Program Directory: V02.02.00
Program Number: 5697-Q02
FMIDs H2AF210, J2AG210 for use with z/OS <is the same, it has
IBM DB2 Accessories Suite for z/OS, V2.2 (5697-Q02) consists
of three features, each bundling components designed to
enhance your use of DB2 for z/OS. Component changes in this
o IBM SPSS Modeler Server Scoring Adapter for DB2 on z/OS
o IBM Data Studio V3.1.1
o IBM Text Search for DB2 for z/OS, which replaces IBM
Omnifind Text Search Server for DB2 for z/OS
o IBM Installable Information Management Software for z/OS
Solutions Information Center
agburke 060001QPDN Visits (1722)
CPU increase is always a customer concern, expecially when it occurs across a release boundary. Many of our customers in DB2 10 have seen a CPU reduction in the DB2 address spaces, and much of this can be attributed to the zIIP eligibility of asynchronous reads/ writes. However there have been some circumstances where the new monitoring or storage allocation behavior has affected CPU negatively.
Here are some APARs to address CPU degredation at the address space level.
PM56363 (HIPER): DIST TCB time increase due to remote SIGNON requ
agburke 060001QPDN Visits (1304)
As you may remember we published the workfile recommendations in informational APAR II14587.
This had to do with the SECQTY attribute and whether or not you set the WFDB
In DB2 10 we allow partition by growth table spaces in the workfile database, and these should be the 'most preferred' when it comes to DGTTs.
Here are 2 APARs that have to do with this functionality in DB2 10.
PM65767: DB2 10 NFM work file separation algo
agburke 060001QPDN Visits (1135)
This PTF closed in June for DB2 9. The customer saw the elapsed time of the utility job go from several hours to a matter of minutes.
PM63505- To improve performance this APAR will avoid externalizing data pages at the end of every FLA (fast log apply) buffer and avoid physically closing of all data sets until after the restore system is completed.
agburke 060001QPDN Visits (875)
In V9 there is a chance that a sequential buffer pool page may be stolen when a random getpage miss occurs. This page was incorrectly not removed from the sequential LRU chain, so it would remain subject to the VPSEQT threshold. This could result in a lower buffer pool hit ratio for frequently used pages and increased synchronous I/O
agburke 060001QPDN Visits (1383)
A DB2 9 for z/OS customer in NFM ran into an issue where DB2 began to run short on 31-bit virtual storage and DSNVMON messages appeared in the log:
DSNV508I -DB2 DSNVMON - DB2 DBM1 BELOW-THE-BAR 351
At the same time the CICS regions processing slowed down significantly, and these threads remained in DB2 longer than normal.
The situation manifested itself in the following way.
While Strobing DB2 (v9 NFM) with CICS Strobe 'hung',
and failed with:
STR3111E STRBFIFA.PrIf2000 Fif* Attach failed
STR3247E STRBFIFR: -STA TRA(PERF) command failed(timeout), shutdown in
progress. The Strobe log contains abend U0522 at 95DBF4BE
Strobe support Recommendations:
1) Set Strobe Parm to DB2IFIFLAG=0010 to enable Auto filtering of DB2
2) Apply PTF V60621A from Strobe maintenance file (42007). This PTF
addresses abend U0522 ABEND @ STRBGBES - STA TRACE(P) T
This PTF has also resolved similar CICS errors at some of our other accounts as well.
Both cases that were repported to us were resolved by it. They reported
that all their CICS' regions 'went down' during a Strobe measurement
because DB2 was not responding but recovered after Strobe ended. The
U0522 abend occurred as well. One of the cases also reported CICS
storage shortages during the measurement. PTF V60621A was the
resolution in each case.
After applying PTF V60621A and updating the DB2IFIFLAG to 0010 Strobe
must be recycled.