--- /dev/null
+/* contrib/pg_stat_statements/pg_stat_statements--1.2--1.3.sql */
+
+-- complain if script is sourced in psql, rather than via ALTER EXTENSION
+\echo Use "ALTER EXTENSION pg_stat_statements UPDATE TO '1.3'" to load this file. \quit
+
+/* First we have to remove them from the extension */
+ALTER EXTENSION pg_stat_statements DROP VIEW pg_stat_statements;
+ALTER EXTENSION pg_stat_statements DROP FUNCTION pg_stat_statements(boolean);
+
+/* Then we can drop them */
+DROP VIEW pg_stat_statements;
+DROP FUNCTION pg_stat_statements(boolean);
+
+/* Now redefine */
+CREATE FUNCTION pg_stat_statements(IN showtext boolean,
+ OUT userid oid,
+ OUT dbid oid,
+ OUT queryid bigint,
+ OUT query text,
+ OUT calls int8,
+ OUT total_time float8,
+ OUT min_time float8,
+ OUT max_time float8,
+ OUT mean_time float8,
+ OUT stddev_time float8,
+ OUT rows int8,
+ OUT shared_blks_hit int8,
+ OUT shared_blks_read int8,
+ OUT shared_blks_dirtied int8,
+ OUT shared_blks_written int8,
+ OUT local_blks_hit int8,
+ OUT local_blks_read int8,
+ OUT local_blks_dirtied int8,
+ OUT local_blks_written int8,
+ OUT temp_blks_read int8,
+ OUT temp_blks_written int8,
+ OUT blk_read_time float8,
+ OUT blk_write_time float8
+)
+RETURNS SETOF record
+AS 'MODULE_PATHNAME', 'pg_stat_statements_1_3'
+LANGUAGE C STRICT VOLATILE;
+
+CREATE VIEW pg_stat_statements AS
+ SELECT * FROM pg_stat_statements(true);
+
+GRANT SELECT ON pg_stat_statements TO PUBLIC;
{
PGSS_V1_0 = 0,
PGSS_V1_1,
- PGSS_V1_2
+ PGSS_V1_2,
+ PGSS_V1_3
} pgssVersion;
/*
{
int64 calls; /* # of times executed */
double total_time; /* total execution time, in msec */
+ double min_time; /* minimim execution time in msec */
+ double max_time; /* maximum execution time in msec */
+ double mean_time; /* mean execution time in msec */
+ double sum_var_time; /* sum of variances in execution time in msec */
int64 rows; /* total # of retrieved or affected rows */
int64 shared_blks_hit; /* # of shared buffer hits */
int64 shared_blks_read; /* # of shared disk blocks read */
PG_FUNCTION_INFO_V1(pg_stat_statements_reset);
PG_FUNCTION_INFO_V1(pg_stat_statements_1_2);
+PG_FUNCTION_INFO_V1(pg_stat_statements_1_3);
PG_FUNCTION_INFO_V1(pg_stat_statements);
static void pgss_shmem_startup(void);
int *query_len_p, int encoding);
static void fill_in_constant_lengths(pgssJumbleState *jstate, const char *query);
static int comp_location(const void *a, const void *b);
+static inline double sqrtd(const double x);
/*
e->counters.calls += 1;
e->counters.total_time += total_time;
+ if (e->counters.calls == 1)
+ {
+ e->counters.min_time = total_time;
+ e->counters.max_time = total_time;
+ e->counters.mean_time = total_time;
+ }
+ else
+ {
+ /*
+ * Welford's method for accurately computing variance.
+ * See <http://www.johndcook.com/blog/standard_deviation/>
+ */
+ double old_mean = e->counters.mean_time;
+
+ e->counters.mean_time +=
+ (total_time - old_mean) / e->counters.calls;
+ e->counters.sum_var_time +=
+ (total_time - old_mean) * (total_time - e->counters.mean_time);
+
+ /* calculate min and max time */
+ if (e->counters.min_time > total_time)
+ e->counters.min_time = total_time;
+ if (e->counters.max_time < total_time)
+ e->counters.max_time = total_time;
+
+ }
e->counters.rows += rows;
e->counters.shared_blks_hit += bufusage->shared_blks_hit;
e->counters.shared_blks_read += bufusage->shared_blks_read;
#define PG_STAT_STATEMENTS_COLS_V1_0 14
#define PG_STAT_STATEMENTS_COLS_V1_1 18
#define PG_STAT_STATEMENTS_COLS_V1_2 19
-#define PG_STAT_STATEMENTS_COLS 19 /* maximum of above */
+#define PG_STAT_STATEMENTS_COLS_V1_3 23
+#define PG_STAT_STATEMENTS_COLS 23 /* maximum of above */
/*
* Retrieve statement statistics.
* expected API version is identified by embedding it in the C name of the
* function. Unfortunately we weren't bright enough to do that for 1.1.
*/
+Datum
+pg_stat_statements_1_3(PG_FUNCTION_ARGS)
+{
+ bool showtext = PG_GETARG_BOOL(0);
+
+ pg_stat_statements_internal(fcinfo, PGSS_V1_3, showtext);
+
+ return (Datum) 0;
+}
+
Datum
pg_stat_statements_1_2(PG_FUNCTION_ARGS)
{
if (api_version != PGSS_V1_2)
elog(ERROR, "incorrect number of output arguments");
break;
+ case PG_STAT_STATEMENTS_COLS_V1_3:
+ if (api_version != PGSS_V1_3)
+ elog(ERROR, "incorrect number of output arguments");
+ break;
default:
elog(ERROR, "incorrect number of output arguments");
}
values[i++] = Int64GetDatumFast(tmp.calls);
values[i++] = Float8GetDatumFast(tmp.total_time);
+ if (api_version >= PGSS_V1_3)
+ {
+ values[i++] = Float8GetDatumFast(tmp.min_time);
+ values[i++] = Float8GetDatumFast(tmp.max_time);
+ values[i++] = Float8GetDatumFast(tmp.mean_time);
+ /*
+ * Note we are calculating the population variance here, not the
+ * sample variance, as we have data for the whole population,
+ * so Bessel's correction is not used, and we don't divide by
+ * tmp.calls - 1.
+ */
+ if (tmp.calls > 1)
+ values[i++] =
+ Float8GetDatumFast(sqrtd(tmp.sum_var_time / tmp.calls));
+ else
+ values[i++] = Float8GetDatumFast(0.0);
+ }
values[i++] = Int64GetDatumFast(tmp.rows);
values[i++] = Int64GetDatumFast(tmp.shared_blks_hit);
values[i++] = Int64GetDatumFast(tmp.shared_blks_read);
Assert(i == (api_version == PGSS_V1_0 ? PG_STAT_STATEMENTS_COLS_V1_0 :
api_version == PGSS_V1_1 ? PG_STAT_STATEMENTS_COLS_V1_1 :
api_version == PGSS_V1_2 ? PG_STAT_STATEMENTS_COLS_V1_2 :
+ api_version == PGSS_V1_3 ? PG_STAT_STATEMENTS_COLS_V1_3 :
-1 /* fail if you forget to update this assert */ ));
tuplestore_putvalues(tupstore, tupdesc, values, nulls);
else
return 0;
}
+
+/*
+ * fast sqrt algorithm: reference from Fast inverse square root algorithms.
+ */
+static inline double
+sqrtd(const double x)
+{
+ double x_half = 0.5 * x;
+ long long int tmp = 0x5FE6EB50C7B537AAl - ( *(long long int*)&x >> 1);
+ double x_result = * (double*)&tmp;
+
+ x_result *= (1.5 - (x_half * x_result * x_result));
+ /* If retry this calculation, it becomes higher precision at sqrt */
+ x_result *= (1.5 - (x_half * x_result * x_result));
+
+ return x_result * x;
+}
<entry>Total time spent in the statement, in milliseconds</entry>
</row>
+ <row>
+ <entry><structfield>min_time</structfield></entry>
+ <entry><type>double precision</type></entry>
+ <entry></entry>
+ <entry>Minimum time spent in the statement, in milliseconds</entry>
+ </row>
+
+ <row>
+ <entry><structfield>max_time</structfield></entry>
+ <entry><type>double precision</type></entry>
+ <entry></entry>
+ <entry>Maximum time spent in the statement, in milliseconds</entry>
+ </row>
+
+ <row>
+ <entry><structfield>mean_time</structfield></entry>
+ <entry><type>double precision</type></entry>
+ <entry></entry>
+ <entry>Mean time spent in the statement, in milliseconds</entry>
+ </row>
+
+ <row>
+ <entry><structfield>stddev_time</structfield></entry>
+ <entry><type>double precision</type></entry>
+ <entry></entry>
+ <entry>Population standard deviation of time spent in the statement, in milliseconds</entry>
+ </row>
+
<row>
<entry><structfield>rows</structfield></entry>
<entry><type>bigint</type></entry>
projects / postgresql / commitdiff