Repository: trafodion Updated Branches: refs/heads/master 3a89dbaee -> 288ed2103
Add Examples for *CONTROL QUERY DEFAULT Statement* in *Trafodion SQL Reference Manual* Project: http://git-wip-us.apache.org/repos/asf/trafodion/repo Commit: http://git-wip-us.apache.org/repos/asf/trafodion/commit/f5c28e96 Tree: http://git-wip-us.apache.org/repos/asf/trafodion/tree/f5c28e96 Diff: http://git-wip-us.apache.org/repos/asf/trafodion/diff/f5c28e96 Branch: refs/heads/master Commit: f5c28e9656b56c58f1009080448169f0be1503c3 Parents: 6b967b6 Author: liu.yu <[email protected]> Authored: Thu May 24 16:54:17 2018 +0800 Committer: liu.yu <[email protected]> Committed: Thu May 24 16:54:17 2018 +0800 ---------------------------------------------------------------------- .../src/asciidoc/_chapters/sql_statements.adoc | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/trafodion/blob/f5c28e96/docs/sql_reference/src/asciidoc/_chapters/sql_statements.adoc ---------------------------------------------------------------------- diff --git a/docs/sql_reference/src/asciidoc/_chapters/sql_statements.adoc b/docs/sql_reference/src/asciidoc/_chapters/sql_statements.adoc index 5a76ffb..ed3656e 100644 --- a/docs/sql_reference/src/asciidoc/_chapters/sql_statements.adoc +++ b/docs/sql_reference/src/asciidoc/_chapters/sql_statements.adoc @@ -1484,16 +1484,21 @@ EXECUTE y; -- uses MYSCHEMA; [[control_query_default_examples]] === Examples of CONTROL QUERY DEFAULT -* Increase the cache refresh time for the histogram cache to two hours (7,200 minutes). +* This example changes the maximum degree of parallelism to 2 for a query. The value must be less than the number of CPUs in the cluster. + ``` -CONTROL QUERY DEFAULT CACHE_HISTOGRAMS_REFRESH_INTERVAL '7200'; +SQL>CONTROL QUERY DEFAULT PARALLEL_NUM_ESPS '2'; + +--- SQL operation complete. ``` -* Reset the CACHE_HISTOGRAMS_REFRESH_INTERVAL attribute to its initial value in the current process: +* This example resets the `PARALLEL_NUM_ESPS` attribute to its system value in the current process, +in this case, the compiler calculates the number of ESPs to be used. + ``` -CONTROL QUERY DEFAULT CACHE_HISTOGRAMS_REFRESH_INTERVAL RESET; +SQL>CONTROL QUERY DEFAULT PARALLEL_NUM_ESPS 'system'; + +--- SQL operation complete. ``` <<<
