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-rw-r--r--contrib/pgstattuple/README.pgstattuple62
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diff --git a/contrib/pgstattuple/README.pgstattuple b/contrib/pgstattuple/README.pgstattuple
index 7237b9a4dc8..804c37c6a91 100644
--- a/contrib/pgstattuple/README.pgstattuple
+++ b/contrib/pgstattuple/README.pgstattuple
@@ -1,27 +1,36 @@
-pgstattuple README 2001/10/01 Tatsuo Ishii
+pgstattuple README 2002/08/22 Tatsuo Ishii
1. What is pgstattuple?
- pgstattuple returns the percentage of the "dead" tuples of a
- table. This will help users to judge if vacuum is needed.
-
- In addition, pgstattuple prints more detailed information using
- NOTICE.
-
-test=# select pgstattuple('tellers');
-NOTICE: physical length: 0.08MB live tuples: 20 (0.00MB, 1.17%) dead tuples: 320 (0.01MB, 18.75%) free/reusable space: 0.01MB (18.06%) overhead: 62.02%
- pgstattuple
--------------
- 18.75
-(1 row)
-
- Above example shows tellers table includes 18.75% dead tuples.
-
- physical length physical size of the table in MB
- live tuples information on the live tuples
- dead tuples information on the dead tuples
- free/reusable space available space
- overhead overhead space
+ pgstattuple returns the table length, percentage of the "dead"
+ tuples of a table and other info. This may help users to determine
+ whether vacuum is necessary or not. Here is an example session:
+
+test=# \x
+Expanded display is on.
+test=# select * from pgstattuple('pg_proc');
+-[ RECORD 1 ]------+-------
+table_len | 458752
+tuple_count | 1470
+tuple_len | 438896
+tuple_percent | 95.67
+dead_tuple_count | 11
+dead_tuple_len | 3157
+dead_tuple_percent | 0.69
+free_space | 8932
+free_percent | 1.95
+
+
+Here are explanations for each column:
+
+table_len -- physical table length in bytes
+tuple_count -- number of live tuples
+tuple_len -- total tuples length in bytes
+tuple_percent -- live tuples in %
+dead_tuple_len -- total dead tuples length in bytes
+dead_tuple_percent -- dead tuples in %
+free_space -- free space in bytes
+free_percent -- free space in %
2. Installing pgstattuple
@@ -31,12 +40,15 @@ NOTICE: physical length: 0.08MB live tuples: 20 (0.00MB, 1.17%) dead tuples: 32
3. Using pgstattuple
- pgstattuple can be called as a function:
+ pgstattuple may be called as a SRF (set returning function) and is
+ defined as follows:
- pgstattuple(TEXT) RETURNS FLOAT8
+ CREATE OR REPLACE FUNCTION pgstattuple(text) RETURNS SETOF pgstattuple_view
+ AS 'MODULE_PATHNAME', 'pgstattuple'
+ LANGUAGE 'c' WITH (isstrict);
- The argument is the table name. pgstattuple returns the percentage
- of the "dead" tuples of a table.
+ The argument is the table name. Note that pgstattuple never
+ returns more than 1 tuple.
4. Notes