Converge all SQL-level statistics timing values to float8 milliseconds.

This patch adjusts the core statistics views to match the decision already
taken for pg_stat_statements, that values representing elapsed time should
be represented as float8 and measured in milliseconds.  By using float8,
we are no longer tied to a specific maximum precision of timing data.
(Internally, it's still microseconds, but we could now change that without
needing changes at the SQL level.)

The columns affected are
pg_stat_bgwriter.checkpoint_write_time
pg_stat_bgwriter.checkpoint_sync_time
pg_stat_database.blk_read_time
pg_stat_database.blk_write_time
pg_stat_user_functions.total_time
pg_stat_user_functions.self_time
pg_stat_xact_user_functions.total_time
pg_stat_xact_user_functions.self_time

The first four of these are new in 9.2, so there is no compatibility issue
from changing them.  The others require a release note comment that they
are now double precision (and can show a fractional part) rather than
bigint as before; also their underlying statistics functions now match
the column definitions, instead of returning bigint microseconds.

3 files changed, 27 insertions, 28 deletions

diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index 094349f3e4..b308e4b581 100644
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	201204291
+#define CATALOG_VERSION_NO	201204301
 
 #endif
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index 5b02f17697..34b77f0191 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -2662,10 +2662,10 @@ DATA(insert OID = 3150 (  pg_stat_get_db_temp_files PGNSP PGUID 12 1 0 0 0 f f f
 DESCR("statistics: number of temporary files written");
 DATA(insert OID = 3151 (  pg_stat_get_db_temp_bytes PGNSP PGUID 12 1 0 0 0 f f f f t f s 1 0 20 "26" _null_ _null_ _null_ _null_ pg_stat_get_db_temp_bytes _null_ _null_ _null_ ));
 DESCR("statistics: number of bytes in temporary files written");
-DATA(insert OID = 2844 (  pg_stat_get_db_blk_read_time	PGNSP PGUID 12 1 0 0 0 f f f f t f s 1 0 20 "26" _null_ _null_ _null_ _null_ pg_stat_get_db_blk_read_time _null_ _null_ _null_ ));
-DESCR("statistics: block read time in microseconds");
-DATA(insert OID = 2845 (  pg_stat_get_db_blk_write_time	PGNSP PGUID 12 1 0 0 0 f f f f t f s 1 0 20 "26" _null_ _null_ _null_ _null_ pg_stat_get_db_blk_write_time _null_ _null_ _null_ ));
-DESCR("statistics: block write time in microseconds");
+DATA(insert OID = 2844 (  pg_stat_get_db_blk_read_time	PGNSP PGUID 12 1 0 0 0 f f f f t f s 1 0 701 "26" _null_ _null_ _null_ _null_ pg_stat_get_db_blk_read_time _null_ _null_ _null_ ));
+DESCR("statistics: block read time, in msec");
+DATA(insert OID = 2845 (  pg_stat_get_db_blk_write_time	PGNSP PGUID 12 1 0 0 0 f f f f t f s 1 0 701 "26" _null_ _null_ _null_ _null_ pg_stat_get_db_blk_write_time _null_ _null_ _null_ ));
+DESCR("statistics: block write time, in msec");
 DATA(insert OID = 2769 ( pg_stat_get_bgwriter_timed_checkpoints PGNSP PGUID 12 1 0 0 0 f f f f t f s 0 0 20 "" _null_ _null_ _null_ _null_ pg_stat_get_bgwriter_timed_checkpoints _null_ _null_ _null_ ));
 DESCR("statistics: number of timed checkpoints started by the bgwriter");
 DATA(insert OID = 2770 ( pg_stat_get_bgwriter_requested_checkpoints PGNSP PGUID 12 1 0 0 0 f f f f t f s 0 0 20 "" _null_ _null_ _null_ _null_ pg_stat_get_bgwriter_requested_checkpoints _null_ _null_ _null_ ));
@@ -2678,10 +2678,10 @@ DATA(insert OID = 2773 ( pg_stat_get_bgwriter_maxwritten_clean PGNSP PGUID 12 1
 DESCR("statistics: number of times the bgwriter stopped processing when it had written too many buffers while cleaning");
 DATA(insert OID = 3075 ( pg_stat_get_bgwriter_stat_reset_time PGNSP PGUID 12 1 0 0 0 f f f f t f s 0 0 1184 "" _null_ _null_ _null_ _null_	pg_stat_get_bgwriter_stat_reset_time _null_ _null_ _null_ ));
 DESCR("statistics: last reset for the bgwriter");
-DATA(insert OID = 3160 ( pg_stat_get_checkpoint_write_time PGNSP PGUID 12 1 0 0 0 f f f f t f s 0 0 20 "" _null_ _null_ _null_ _null_ pg_stat_get_checkpoint_write_time _null_ _null_ _null_ ));
-DESCR("statistics: total amount of checkpoint time spent writing buffers to disk");
-DATA(insert OID = 3161 ( pg_stat_get_checkpoint_sync_time PGNSP PGUID 12 1 0 0 0 f f f f t f s 0 0 20 "" _null_ _null_ _null_ _null_ pg_stat_get_checkpoint_sync_time _null_ _null_ _null_ ));
-DESCR("statistics: total amount of checkpoint time spent synchronizing buffers to disk");
+DATA(insert OID = 3160 ( pg_stat_get_checkpoint_write_time PGNSP PGUID 12 1 0 0 0 f f f f t f s 0 0 701 "" _null_ _null_ _null_ _null_ pg_stat_get_checkpoint_write_time _null_ _null_ _null_ ));
+DESCR("statistics: checkpoint time spent writing buffers to disk, in msec");
+DATA(insert OID = 3161 ( pg_stat_get_checkpoint_sync_time PGNSP PGUID 12 1 0 0 0 f f f f t f s 0 0 701 "" _null_ _null_ _null_ _null_ pg_stat_get_checkpoint_sync_time _null_ _null_ _null_ ));
+DESCR("statistics: checkpoint time spent synchronizing buffers to disk, in msec");
 DATA(insert OID = 2775 ( pg_stat_get_buf_written_backend PGNSP PGUID 12 1 0 0 0 f f f f t f s 0 0 20 "" _null_ _null_ _null_ _null_ pg_stat_get_buf_written_backend _null_ _null_ _null_ ));
 DESCR("statistics: number of buffers written by backends");
 DATA(insert OID = 3063 ( pg_stat_get_buf_fsync_backend PGNSP PGUID 12 1 0 0 0 f f f f t f s 0 0 20 "" _null_ _null_ _null_ _null_ pg_stat_get_buf_fsync_backend _null_ _null_ _null_ ));
@@ -2691,10 +2691,10 @@ DESCR("statistics: number of buffer allocations");
 
 DATA(insert OID = 2978 (  pg_stat_get_function_calls		PGNSP PGUID 12 1 0 0 0 f f f f t f s 1 0 20 "26" _null_ _null_ _null_ _null_ pg_stat_get_function_calls _null_ _null_ _null_ ));
 DESCR("statistics: number of function calls");
-DATA(insert OID = 2979 (  pg_stat_get_function_time			PGNSP PGUID 12 1 0 0 0 f f f f t f s 1 0 20 "26" _null_ _null_ _null_ _null_ pg_stat_get_function_time _null_ _null_ _null_ ));
-DESCR("statistics: execution time of function");
-DATA(insert OID = 2980 (  pg_stat_get_function_self_time	PGNSP PGUID 12 1 0 0 0 f f f f t f s 1 0 20 "26" _null_ _null_ _null_ _null_ pg_stat_get_function_self_time _null_ _null_ _null_ ));
-DESCR("statistics: self execution time of function");
+DATA(insert OID = 2979 (  pg_stat_get_function_total_time	PGNSP PGUID 12 1 0 0 0 f f f f t f s 1 0 701 "26" _null_ _null_ _null_ _null_ pg_stat_get_function_total_time _null_ _null_ _null_ ));
+DESCR("statistics: total execution time of function, in msec");
+DATA(insert OID = 2980 (  pg_stat_get_function_self_time	PGNSP PGUID 12 1 0 0 0 f f f f t f s 1 0 701 "26" _null_ _null_ _null_ _null_ pg_stat_get_function_self_time _null_ _null_ _null_ ));
+DESCR("statistics: self execution time of function, in msec");
 
 DATA(insert OID = 3037 (  pg_stat_get_xact_numscans				PGNSP PGUID 12 1 0 0 0 f f f f t f v 1 0 20 "26" _null_ _null_ _null_ _null_ pg_stat_get_xact_numscans _null_ _null_ _null_ ));
 DESCR("statistics: number of scans done for table/index in current transaction");
@@ -2716,10 +2716,10 @@ DATA(insert OID = 3045 (  pg_stat_get_xact_blocks_hit			PGNSP PGUID 12 1 0 0 0 f
 DESCR("statistics: number of blocks found in cache in current transaction");
 DATA(insert OID = 3046 (  pg_stat_get_xact_function_calls		PGNSP PGUID 12 1 0 0 0 f f f f t f v 1 0 20 "26" _null_ _null_ _null_ _null_ pg_stat_get_xact_function_calls _null_ _null_ _null_ ));
 DESCR("statistics: number of function calls in current transaction");
-DATA(insert OID = 3047 (  pg_stat_get_xact_function_time		PGNSP PGUID 12 1 0 0 0 f f f f t f v 1 0 20 "26" _null_ _null_ _null_ _null_ pg_stat_get_xact_function_time _null_ _null_ _null_ ));
-DESCR("statistics: execution time of function in current transaction");
-DATA(insert OID = 3048 (  pg_stat_get_xact_function_self_time	PGNSP PGUID 12 1 0 0 0 f f f f t f v 1 0 20 "26" _null_ _null_ _null_ _null_ pg_stat_get_xact_function_self_time _null_ _null_ _null_ ));
-DESCR("statistics: self execution time of function in current transaction");
+DATA(insert OID = 3047 (  pg_stat_get_xact_function_total_time	PGNSP PGUID 12 1 0 0 0 f f f f t f v 1 0 701 "26" _null_ _null_ _null_ _null_ pg_stat_get_xact_function_total_time _null_ _null_ _null_ ));
+DESCR("statistics: total execution time of function in current transaction, in msec");
+DATA(insert OID = 3048 (  pg_stat_get_xact_function_self_time	PGNSP PGUID 12 1 0 0 0 f f f f t f v 1 0 701 "26" _null_ _null_ _null_ _null_ pg_stat_get_xact_function_self_time _null_ _null_ _null_ ));
+DESCR("statistics: self execution time of function in current transaction, in msec");
 
 DATA(insert OID = 2230 (  pg_stat_clear_snapshot		PGNSP PGUID 12 1 0 0 0 f f f f f f v 0 0 2278 "" _null_ _null_ _null_ _null_	pg_stat_clear_snapshot _null_ _null_ _null_ ));
 DESCR("statistics: discard current transaction's statistics snapshot");
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 8549d17f28..3583bbe301 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -233,7 +233,7 @@ typedef struct PgStat_MsgTabstat
 	int			m_nentries;
 	int			m_xact_commit;
 	int			m_xact_rollback;
-	PgStat_Counter	  m_block_read_time;
+	PgStat_Counter	  m_block_read_time;		/* times in microseconds */
 	PgStat_Counter	  m_block_write_time;
 	PgStat_TableEntry m_entry[PGSTAT_NUM_TABENTRIES];
 } PgStat_MsgTabstat;
@@ -366,7 +366,7 @@ typedef struct PgStat_MsgBgWriter
 	PgStat_Counter m_buf_written_backend;
 	PgStat_Counter m_buf_fsync_backend;
 	PgStat_Counter m_buf_alloc;
-	PgStat_Counter m_checkpoint_write_time;
+	PgStat_Counter m_checkpoint_write_time;		/* times in milliseconds */
 	PgStat_Counter m_checkpoint_sync_time;
 } PgStat_MsgBgWriter;
 
@@ -407,8 +407,8 @@ typedef struct PgStat_MsgTempFile
 typedef struct PgStat_FunctionCounts
 {
 	PgStat_Counter f_numcalls;
-	instr_time	f_time;
-	instr_time	f_time_self;
+	instr_time	f_total_time;
+	instr_time	f_self_time;
 } PgStat_FunctionCounts;
 
 /* ----------
@@ -429,8 +429,8 @@ typedef struct PgStat_FunctionEntry
 {
 	Oid			f_id;
 	PgStat_Counter f_numcalls;
-	PgStat_Counter f_time;		/* times in microseconds */
-	PgStat_Counter f_time_self;
+	PgStat_Counter f_total_time;		/* times in microseconds */
+	PgStat_Counter f_self_time;
 } PgStat_FunctionEntry;
 
 /* ----------
@@ -545,7 +545,6 @@ typedef struct PgStat_StatDBEntry
 
 	TimestampTz stat_reset_timestamp;
 
-
 	/*
 	 * tables and functions must be last in the struct, because we don't write
 	 * the pointers out to the stats file.
@@ -601,8 +600,8 @@ typedef struct PgStat_StatFuncEntry
 
 	PgStat_Counter f_numcalls;
 
-	PgStat_Counter f_time;		/* times in microseconds */
-	PgStat_Counter f_time_self;
+	PgStat_Counter f_total_time;		/* times in microseconds */
+	PgStat_Counter f_self_time;
 } PgStat_StatFuncEntry;
 
 
@@ -705,7 +704,7 @@ typedef struct PgStat_FunctionCallUsage
 	/* NULL means we are not tracking the current function call */
 	PgStat_FunctionCounts *fs;
 	/* Total time previously charged to function, as of function start */
-	instr_time	save_f_time;
+	instr_time	save_f_total_time;
 	/* Backend-wide total time as of function start */
 	instr_time	save_total;
 	/* system clock as of function start */
@@ -730,7 +729,7 @@ extern char *pgstat_stat_filename;
 extern PgStat_MsgBgWriter BgWriterStats;
 
 /*
- * Updated by pgstat_count_time_* macros.
+ * Updated by pgstat_count_buffer_*_time macros
  */
 extern PgStat_Counter pgStatBlockReadTime;
 extern PgStat_Counter pgStatBlockWriteTime;