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| author | Simon Riggs <simon@2ndQuadrant.com> | 2017-04-05 18:00:42 -0400 |
|---|---|---|
| committer | Simon Riggs <simon@2ndQuadrant.com> | 2017-04-05 18:00:42 -0400 |
| commit | 2686ee1b7ccfb9214064d4d2a98ea77382880306 (patch) | |
| tree | 32095d935e240b93ed30b1e86c2efa161cffa4dd /src/bin/psql/describe.c | |
| parent | 00b6b6feb12cef53737287b67ecef6aff1f1d8ab (diff) | |
| download | postgresql-2686ee1b7ccfb9214064d4d2a98ea77382880306.tar.gz postgresql-2686ee1b7ccfb9214064d4d2a98ea77382880306.zip | |
Collect and use multi-column dependency stats
Follow on patch in the multi-variate statistics patch series.
CREATE STATISTICS s1 WITH (dependencies) ON (a, b) FROM t;
ANALYZE;
will collect dependency stats on (a, b) and then use the measured
dependency in subsequent query planning.
Commit 7b504eb282ca2f5104b5c00b4f05a3ef6bb1385b added
CREATE STATISTICS with n-distinct coefficients. These are now
specified using the mutually exclusive option WITH (ndistinct).
Author: Tomas Vondra, David Rowley
Reviewed-by: Kyotaro HORIGUCHI, Álvaro Herrera, Dean Rasheed, Robert Haas
and many other comments and contributions
Discussion: https://postgr.es/m/56f40b20-c464-fad2-ff39-06b668fac47c@2ndquadrant.com
Diffstat (limited to 'src/bin/psql/describe.c')
| -rw-r--r-- | src/bin/psql/describe.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c index b0f3e5e3470..2ef06261e69 100644 --- a/src/bin/psql/describe.c +++ b/src/bin/psql/describe.c @@ -2331,7 +2331,8 @@ describeOneTableDetails(const char *schemaname, " FROM ((SELECT pg_catalog.unnest(stakeys) AS attnum) s\n" " JOIN pg_catalog.pg_attribute a ON (starelid = a.attrelid AND\n" "a.attnum = s.attnum AND not attisdropped))) AS columns,\n" - " (staenabled::char[] @> '{d}'::char[]) AS ndist_enabled\n" + " (staenabled::char[] @> '{d}'::char[]) AS ndist_enabled,\n" + " (staenabled::char[] @> '{f}'::char[]) AS deps_enabled\n" "FROM pg_catalog.pg_statistic_ext stat WHERE starelid = '%s'\n" "ORDER BY 1;", oid); @@ -2348,7 +2349,7 @@ describeOneTableDetails(const char *schemaname, for (i = 0; i < tuples; i++) { - int cnt = 0; + bool gotone = false; printfPQExpBuffer(&buf, " "); @@ -2361,7 +2362,12 @@ describeOneTableDetails(const char *schemaname, if (strcmp(PQgetvalue(result, i, 5), "t") == 0) { appendPQExpBufferStr(&buf, "ndistinct"); - cnt++; + gotone = true; + } + + if (strcmp(PQgetvalue(result, i, 6), "t") == 0) + { + appendPQExpBuffer(&buf, "%sdependencies", gotone ? ", " : ""); } appendPQExpBuffer(&buf, ") ON (%s)", |