BufferPool Performance Analysis Beyond the Basic Hit Ratio.....

BufferPool Performance Analysis Beyond the Basic Hit Ratio.....

835+*/********************************************************************/

836+*/* IFC ID 0006 FOR RMID 10 RECORDS THE ID OF THE DATA SET BEFORE */

837+*/* A READ I/O OPERATION */

838+*/********************************************************************/

839+*

840+QW0006 DSECT IFCID(QWHS0006)

841+QW0006DB DS XL2 DATABASE ID (DBID)

842+QW0006OB DS XL2 PAGESET OBID

843+QW0006BP DS F BUFFER POOL INTERNAL ID (0-49 and 80-89)

844+*

845+QW0006PN DS XL3 FIRST PAGE NUMBER TO BE READ

846+QW0006F DS C FLAG FOR TYPE OF READ

847+QW0006FS EQU C'S' SEQUENTIAL PREFETCH REQUEST

848+QW0006FL EQU C'L' LIST PREFETCH REQUEST

849+QW0006FD EQU C'D' DYNAMIC SEQUENTIAL PREFETCH REQUEST

850+QW0006FR EQU C'R' READ REQUEST

851+QW0006AC DS F ACE TOKEN OF REQUESTOR

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The IFCID 6 record shows us the type of physical read that takes place, and adds the Dynamic Prefetch information. The header (not shown) contains a timestamp that can be used together with the 7 record to get elapsed time.