When the STALL command is used or when <PF6> STATS is pressed at any time after having used the STALL command, the following panel can be accessed by pressing <PF3> TABLE STATISTICS during FIND STATISTICS display.
Find Statistics (DQEC0)
=> Current Dataquery FIND/SELECT Statistics. ------------------------------------------------------------------------DQEC0 DATAQUERY: FIND STATISTICS QUERY NAME: PROGRAMS ----------------------------------------------------------------------------- TNM-BID STRG NQ RELS RELO I/O E-I/O E-ROWS CARD RQAS KEY F-BUF ------- ----- -- ---- ---- ------- ------- ------- ------- ---- -------- ----- PGM- 2 336 N 5 N/A N/A N/A 72 ----------------------------------------------------------------------------- <PF1> HELP <PF2> RETURN <PF3> OVERALL STATS
Action
Note the query statistics if a problem occurs during query execution and be prepared to report the information if you require assistance with problem resolution.
The FIND/SELECT Statistics panel appears when you display query output on your screen, press <PF6> STATS, and press <PF3> TABLE STATISTICS after the Query Statistics panel (DQEF0) appears. It provides further statistical information about query processing.
Panel Description
Table name and database ID.
Length of permanent storage for this table, including the request area, RQA size, nonqualifying with list, and overhead. (CA Dataquery and the Compound Boolean Selection facility of CA Datacom/DB dynamically handle the search optimization. CA Dataquery uses predicates (a WITH in a DQL Mode query FIND statement) to build a Compound Boolean Selection Request Qualification Area (RQA), converting the selection criteria in a query's statements into the Compound Boolean Selection format.)
Nonqualifying predicates.
Related subject, column, key or value.
Related object, column, or key.
Number of I/Os for this execution.
Estimated I/O from Compound Boolean Selection and estimate calls for join optimization. E-I/O and E-ROWS apply to a single table. The values are calculated using the E-I/O and E-ROWS values for each table, the relative cardinalities of the tables, whether the related objects are indexed or not, and the number of rows requested in the query. The numbers shown are normally the values received from the Compound Boolean Selection Facility only for the first table listed on DQEC0. The other tables have been adjusted based on relative cardinality, and so forth.
The number of rows on the table, if joining. The relative cardinality of the tables figures into join optimization.
Shows whether a query is nearing the 9999 RQA limitation.
Means one of two things, depending on whether the name is followed by an R or a G.
R indicates that Compound Boolean Selection used this key because it is a related object in the table and the ratio of table cardinalities indicated that the key might optimize the join.
G indicates that Compound Boolean Selection suggested using the key if executing in batch and only for the primary table in the search.
Storage used for buffering for nonqualifying predicates or cross-joined WITH statements.
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