syssqexplain table

The syssqexplain pseudo table stores information about SQL queries.

The information stored includes the plan of the query optimizer, an estimate of the number of rows returned, and the relative cost of the query.

Table 1. The syssqexplain pseudo table
Column Type Description
sqx_sessionid INTEGER The session ID associated with the SQL statement.
sqx_sdbno INTEGER The position of the query in the array of session IDs.
sqx_iscurrent CHAR Whether the query is the current SQL statement.
sqx_executions INTEGER The total number of executions of the query.
sqx_cumtime FLOAT The cumulative time to run the query.
Important: If SQL tracing is disabled a zero is shown.
sqx_bufreads INTEGER The number of buffer reads performed while running the query.
Important: If SQL tracing is disabled a zero is shown.
sqx_pagereads INTEGER The number of page reads performed while running the query.
Important: If SQL tracing is disabled a zero is shown.
sqx_bufwrites INTEGER The number of buffer writes performed while running the query.
Important: If SQL tracing is disabled a zero is shown.
sqx_pagewrites INTEGER The number of page writes performed while running the query.
Important: If SQL tracing is disabled a zero is shown.
sqx_totsorts INTEGER The total number of sorts performed while running the query.
Important: If SQL tracing is disabled a zero is shown.
sqx_dsksorts INTEGER The number of disk sorts performed while running the query.
Important: If SQL tracing is disabled a zero is shown.
sqx_sortspmax INTEGER The maximum disk space required by a sort.
sqx_conbno SMALLINT The position in the conblock list.
sqx_ismain CHAR Whether the query is in the main block for the statement.
sqx_selflag VARCHAR(200,0) The type of SQL statement, for example: SELECT, UPDATE, DELETE.
sqx_estcost INTEGER The estimated cost of the query.
sqx_estrows INTEGER The estimated number of rows returned by the query.
sqx_seqscan SMALLINT The number of sequential scans used by the query.
sqx_srtscan SMALLINT The number of sort scans used by the query.
sqx_autoindex SMALLINT The number of autoindex scans used by the query.
sqx_index SMALLINT The number of index paths used by the query.
sqx_remsql SMALLINT The number of remote paths used by the query.
sqx_mrgjoin SMALLINT The number of sort-merge joins used by the query.
sqx_dynhashjoin SMALLINT The number of dynamic hash joins used by the query.
sqx_keyonly SMALLINT The number of key-only scans used by the query.
sqx_tempfile SMALLINT The number of temporary files used by the query.
sqx_tempview SMALLINT The number of temporary tables for views created by the query.
sqx_secthreads SMALLINT The number of secondary threads used by the query.
sqx_sqlstatement CHAR The SQL query that was run.

Copyright© 2019 HCL Technologies Limited