PG-193: Comment based tags to identify different parameters.

Makefile

@@ -11,7 +11,7 @@ PGFILEDESC = "pg_stat_monitor - execution statistics of SQL statements"
 LDFLAGS_SL += $(filter -lm, $(LIBS)) 
 
 REGRESS_OPTS = --temp-config $(top_srcdir)/contrib/pg_stat_monitor/pg_stat_monitor.conf --inputdir=regression
-REGRESS = basic version guc counters relations database top_query application_name cmd_type error state rows 
+REGRESS = basic version guc counters relations database top_query application_name cmd_type error state rows tags
 
 # Disabled because these tests require "shared_preload_libraries=pg_stat_statements",
 # which typical installcheck users do not have (e.g. buildfarm clients).

pg_stat_monitor--1.0.sql

@@ -77,7 +77,8 @@ CREATE FUNCTION pg_stat_monitor_internal(IN showtext boolean,
     OUT cpu_sys_time        float8,
     OUT wal_records 		int8,
     OUT wal_fpi 			int8,
-    OUT wal_bytes 			numeric
+    OUT wal_bytes 			numeric,
+    OUT comments 			TEXT
 )
 RETURNS SETOF record
 AS 'MODULE_PATHNAME', 'pg_stat_monitor'
@@ -144,6 +145,7 @@ CREATE VIEW pg_stat_monitor AS SELECT
     queryid,
     top_queryid,
     query,
+	comments,
 	planid,
 	query_plan,
 	(SELECT query from pg_stat_monitor_internal(true) s where s.queryid = p.top_queryid) AS top_query,

pg_stat_monitor.c

@@ -15,13 +15,14 @@
  *-------------------------------------------------------------------------
  */
 #include "postgres.h"
+#include <regex.h>
 #include "commands/explain.h"
 #include "pg_stat_monitor.h"
 
 PG_MODULE_MAGIC;
 
 #define BUILD_VERSION                   "devel"
-#define PG_STAT_STATEMENTS_COLS         51  /* maximum of above */
+#define PG_STAT_STATEMENTS_COLS         52  /* maximum of above */
 #define PGSM_TEXT_FILE                  "/tmp/pg_stat_monitor_query"
 
 #define PGUNSIXBIT(val) (((val) & 0x3F) + '0')
@@ -73,6 +74,7 @@ static struct rusage  rusage_end;
 static unsigned char *pgss_qbuf[MAX_BUCKETS];
 static char *pgss_explain(QueryDesc *queryDesc);
 
+static char *extract_query_comments(const char *query);
 static int  get_histogram_bucket(double q_time);
 static bool IsSystemInitialized(void);
 static void dump_queries_buffer(int bucket_id, unsigned char *buf, int buf_len);
@@ -893,6 +895,7 @@ pgss_update_entry(pgssEntry *entry,
 						int bucketid,
 						uint64 queryid,
 						const char *query,
+						const char *comments,
 						PlanInfo *plan_info,
 						CmdType cmd_type,
 						SysInfo *sys_info,
@@ -910,6 +913,7 @@ pgss_update_entry(pgssEntry *entry,
 	pgssSharedState     *pgss = pgsm_get_ss();
 	double              old_mean;
 	int             	message_len = error_info ? strlen (error_info->message) : 0;
+	int             	comments_len = comments ? strlen (comments) : 0;
 	int             	sqlcode_len = error_info ? strlen (error_info->sqlcode) : 0;
 	int             	plan_text_len = plan_info ? strlen (plan_info->plan_text) : 0;
 
@@ -922,6 +926,7 @@ pgss_update_entry(pgssEntry *entry,
 		if (reset)
 			memset(&entry->counters, 0, sizeof(Counters));
 
+		_snprintf(e->counters.info.comments, comments, comments_len, COMMENTS_LEN);
 		e->counters.state = kind;
 		if (kind == PGSS_PLAN)
 		{
@@ -1204,13 +1209,15 @@ pgss_store(uint64 queryid,
 	uint64 			dbid = MyDatabaseId;
 	uint64 			ip = pg_get_client_addr();
 	uint64			planid = plan_info ? plan_info->planid: 0;
-
+	char            *comments;
 	/*  Monitoring is disabled */
 	if (!PGSM_ENABLED)
 		return;
 
 	Assert(query != NULL);
 
+	comments = extract_query_comments(query);
+
 	/* Safety check... */
 	if (!IsSystemInitialized() || !pgss_qbuf[pgss->current_wbucket])
 		return;
@@ -1258,6 +1265,7 @@ pgss_store(uint64 queryid,
 							bucketid,			/* bucketid */
 							queryid,			/* queryid */
 							query, 				/* query */
+							comments,			/* comments */
 							plan_info,			/* PlanInfo */
 							cmd_type,			/* CmdType */
 							sys_info,			/* SysInfo */
@@ -1364,7 +1372,7 @@ pg_stat_monitor_internal(FunctionCallInfo fcinfo,
 	if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
 		elog(ERROR, "pg_stat_monitor: return type must be a row type");
 
-	if (tupdesc->natts != 48)
+	if (tupdesc->natts != 49)
 		elog(ERROR, "pg_stat_monitor: incorrect number of output arguments, required %d", tupdesc->natts);
 
 	tupstore = tuplestore_begin_heap(true, false, work_mem);
@@ -1658,6 +1666,12 @@ pg_stat_monitor_internal(FunctionCallInfo fcinfo,
 											Int32GetDatum(-1));
 			/* wal_bytes at column number 46 */
 			values[i++] = wal_bytes;
+
+			/* application_name at column number 47 */
+			if (strlen(tmp.info.comments) > 0)
+				values[i++] = CStringGetTextDatum(tmp.info.comments);
+			else
+				nulls[i++] = true;
 		}
 		tuplestore_putvalues(tupstore, tupdesc, values, nulls);
 	}
@@ -3049,3 +3063,26 @@ get_histogram_timings(PG_FUNCTION_ARGS)
 	return CStringGetTextDatum(text_str);
 }
 
+char *
+extract_query_comments(const char *query)
+{
+	regex_t    preg;
+	char       *pattern = "/\\*.*\\*/";
+	int        rc;
+	size_t     nmatch = 1;
+	regmatch_t pmatch;
+	char       *comments = palloc0(512);
+
+   rc = regcomp(&preg, pattern, 0);
+   if (rc != 0)
+   {
+	   printf("regcomp() failed, returning nonzero (%d)\n", rc);
+	   return "";
+   }
+   rc = regexec(&preg, query, nmatch, &pmatch, 0);
+   if (rc != 0)
+	   return "";
+   sprintf(comments, "%.*s", pmatch.rm_eo - pmatch.rm_so -4, &query[pmatch.rm_so + 2]);
+   regfree(&preg);
+   return comments;
+}

pg_stat_monitor.h

@@ -78,6 +78,7 @@
 #define CMD_LST				10
 #define CMD_LEN				20
 #define APPLICATIONNAME_LEN	100
+#define COMMENTS_LEN        512
 #define PGSM_OVER_FLOW_MAX	10
 #define PLAN_TEXT_LEN		1024
 /* the assumption of query max nested level */
@@ -211,6 +212,7 @@ typedef struct QueryInfo
 	uint64		parentid;					/* parent queryid of current query*/
 	int64       type; 						/* type of query, options are query, info, warning, error, fatal */
 	char		application_name[APPLICATIONNAME_LEN];
+	char		comments[COMMENTS_LEN];
 	char		relations[REL_LST][REL_LEN];         /* List of relation involved in the query */
 	int			num_relations;				/*  Number of relation in the query */
 	CmdType		cmd_type;                   /* query command type SELECT/UPDATE/DELETE/INSERT */

regression/expected/tags.out

@@ -0,0 +1,28 @@
+CREATE EXTENSION pg_stat_monitor;
+SELECT pg_stat_monitor_reset();
+ pg_stat_monitor_reset 
+-----------------------
+ 
+(1 row)
+
+SELECT 1 AS num /* { "application", psql_app, "real_ip", 192.168.1.3) */;
+ num 
+-----
+   1
+(1 row)
+
+SELECT query, comments FROM pg_stat_monitor ORDER BY query COLLATE "C";
+                                  query                                  |                       comments                       
+-------------------------------------------------------------------------+------------------------------------------------------
+ SELECT $1 AS num                                                        |  { "application", psql_app, "real_ip", 192.168.1.3) 
+ SELECT pg_stat_monitor_reset();                                         | 
+ SELECT query, comments FROM pg_stat_monitor ORDER BY query COLLATE "C"; | 
+(3 rows)
+
+SELECT pg_stat_monitor_reset();
+ pg_stat_monitor_reset 
+-----------------------
+ 
+(1 row)
+
+DROP EXTENSION pg_stat_monitor;

regression/sql/tags.sql

@@ -0,0 +1,6 @@
+CREATE EXTENSION pg_stat_monitor;
+SELECT pg_stat_monitor_reset();
+SELECT 1 AS num /* { "application", psql_app, "real_ip", 192.168.1.3) */;
+SELECT query, comments FROM pg_stat_monitor ORDER BY query COLLATE "C";
+SELECT pg_stat_monitor_reset();
+DROP EXTENSION pg_stat_monitor;