Real-time statistics

You can use DB2’s ability to collect statistics in real time to help monitor the activity against your packaged application objects. H2 database Real-time statistics lets DB2 collect statistics on table spaces and index spaces and periodically write this information to two user-defined tables. Nexus 5 data recovery Beginning with DB2 9, these tables are an integral part of the system catalog. Data recovery uk User-written queries and programs, or a DB2-supplied stored procedure, or Control Center, can use the statistics to make decisions for object maintenance.

DB2 constantly collects statistics for database objects and keeps the statistics in virtual storage. Database collation The statistics are calculated and updated asynchronously during externalization. Database yugioh To externalize the statistics, the environment must be properly set up. Top 10 data recovery software free A new set of DB2 objects must be created to let DB2 write the statistics. Data recovery vancouver bc SDSNSAMP(DSNTESS) contains the information necessary to set up these objects.

These tables are kept in a database named DSNRTSDB, which must be started to externalize the statistics being held in virtual storage. 7 data recovery suite crack DB2 populates the tables with one row per table space or index space, or one row per partition. Database normalization definition For tables that are shared in a data-sharing environment, each member writes its own statistics to the RTS tables.

Statistics that are collected to help with COPY determination include distinct updated pages and changes since the last COPY execution and the RBA/LRSN of first update since the last COPY.

DB2 gathers statistics since the last REORG or REBUILD to determine how our data physically looks after certain processes occur, for example, batch inserts, so you can take appropriate actions if necessary. Data recovery wizard These statistics include:

This example shows how to identify when a tablespace has to be copied because more than 30 percent of the pages changed since the last image copy was taken.

This example compares the last RUNSTATS timestamp to the timestamp of the last REORG on the same object. Data recovery video If the date of the last REORG is more recent than the last RUNSTATS, it may be time to execute RUNSTATS.

This example may be useful to monitor the number of records that were inserted since the last REORG or LOAD REPLACE that are not well-clustered with respect to the clustering index. Database query example Well-clustered means that the record was inserted into a page that was within 16 pages of the ideal candidate page (determined by the clustering index). Database migration You can use the SYSTABLESPACESTATS table value REORGUNCLUSTINS to determine if you have to run REORG after a series of inserts.

DB2 includes a stored procedure, DSNACCOR, to help with this process, and possibly even work toward automating the whole determination/utility execution process. Data recovery free DSNACCOR is a sample procedure that queries the RTS tables to determine which objects:

DSNACCOR creates and uses its own declared temporary tables and must run in a WLM address space. Database vs spreadsheet The output of the stored procedure provides recommendations by using a predetermined set of criteria in formulas that use the RTS and user input for their calculations. Database name sql DSNACCOR can make recommendations for COPY, REORG, RUNSTATS, EXTENTS, RESTRICT, or for one or more of your choices and for specific object types, such as table spaces and indexes.