このEXPLAINリクエスト修飾子は、DELETE文を実行するための手順およびDELETEおよびSELECTの制約の適用結果を示します。
EXPLAIN DELETE FROM rls_tbl WHERE col1=2;
システムは、このEXPLAINテキストを返します。
*** Help information returned. 10 rows.
*** Total elapsed time was 1 second.
Explanation
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1) First, we do a single-AMP DELETE from RS.rls_tbl by way of the
primary index "RS.rls_tbl.col1 = 2" with a residual condition of (
"((SYSLIB.DELETELEVEL (RS.rls_tbl.levels ))= 'T') AND
(((SYSLIB.SELECTLEVEL (2, RS.rls_tbl.levels ))= 'T') AND
(((SYSLIB.DELETECATEGORIES (RS.rls_tbl.categories ))= 'T') AND
((SYSLIB.SELECTCATEGORIES ('90000000'XB, RS.rls_tbl.categories ))=
'T')))"). The size is estimated with no confidence to be 2 rows.
The estimated time for this step is 0.01 seconds.
-> No rows are returned to the user as the result of statement 1.
The total estimated time is 0.01 seconds.