8000 Code and docs review for pg_column_size() patch. · postgrespro/postgres_cluster@0001e98 · GitHub
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Code and docs review for pg_column_size() patch.
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‎doc/src/sgml/func.sgml

Lines changed: 65 additions & 44 deletions
Original file line numberDiff line numberDiff line change
@@ -1,5 +1,5 @@
11
<!--
2-
$PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.275 2005/07/30 22:53:15 tgl Exp $
2+
$PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.276 2005/08/02 16:11:56 tgl Exp $
33
PostgreSQL documentation
44
-->
55

@@ -2206,14 +2206,6 @@ PostgreSQL documentation
22062206
<entry><literal>5</literal></entry>
22072207
</row>
22082208

2209-
<row>
2210-
<entry><literal><function>pg_column_size</function>(<parameter>string</parameter>)</literal></entry>
2211-
<entry><type>integer</type></entry>
2212-
<entry>Number of bytes required to store the value, which might be compressed</entry>
2213-
<entry><literal>pg_column_size('jo\\000se'::bytea)</literal></entry>
2214-
<entry><literal>5</literal></entry>
2215-
</row>
2216-
22172209
<row>
22182210
<entry><literal><function>position</function>(<parameter>substring</parameter> in <parameter>string</parameter>)</literal></entry>
22192211
<entry><type>integer</type></entry>
@@ -9181,11 +9173,29 @@ SELECT set_config('log_statement_stats', 'off', false);
91819173
</para>
91829174

91839175
<para>
9184-
The functions shown in <xref
9185-
linkend="functions-admin-dbsize"> calculate the actual disk space
9186-
usage of database objects.
9176+
The functions shown in <xref linkend="functions-admin-dbsize"> calculate
9177+
the actual disk space usage of database objects.
91879178
</para>
91889179

9180+
<indexterm zone="functions-admin">
9181+
<primary>pg_column_size</primary>
9182+
</indexterm>
9183+
<indexterm zone="functions-admin">
9184+
<primary>pg_tablespace_size</primary>
9185+
</indexterm>
9186+
<indexterm zone="functions-admin">
9187+
<primary>pg_database_size</primary>
9188+
</indexterm>
9189+
<indexterm zone="functions-admin">
9190+
<primary>pg_relation_size</primary>
9191+
</indexterm>
9192+
<indexterm zone="functions-admin">
9193+
<primary>pg_complete_relation_size</primary>
9194+
</indexterm>
9195+
<indexterm zone="functions-admin">
9196+
<primary>pg_size_pretty</primary>
9197+
</indexterm>
9198+
91899199
<table id="functions-admin-dbsize">
91909200
<title>Database Object Size Functions</title>
91919201
<tgroup cols="3">
@@ -9195,97 +9205,108 @@ SELECT set_config('log_statement_stats', 'off', false);
91959205
</thead>
91969206

91979207
<tbody>
9208+
<row>
9209+
<entry><function>pg_column_size</function>(<parameter>any</parameter>)</entry>
9210+
<entry><type>integer</type></entry>
9211+
<entry>Number of bytes used to store a particular value (possibly compressed)</entry>
9212+
</row>
91989213
<row>
91999214
<entry>
92009215
<literal><function>pg_tablespace_size</function>(<parameter>oid</parameter>)</literal>
92019216
</entry>
9202-
<entry><type>int8</type></entry>
9203-
<entry>Calculates the total disk space used by the tablespace with the specified OID</entry>
9217+
<entry><type>bigint</type></entry>
9218+
<entry>Total disk space used by the tablespace with the specified OID</entry>
92049219
</row>
92059220
<row>
92069221
<entry>
92079222
<literal><function>pg_tablespace_size</function>(<parameter>name</parameter>)</literal>
92089223
</entry>
9209-
<entry><type>int8</type></entry>
9210-
<entry>Calculates the total disk space used by the tablespace with the specified name</entry>
9224+
<entry><type>bigint</type></entry>
9225+
<entry>Total disk space used by the tablespace with the specified name</entry>
92119226
</row>
92129227
<row>
92139228
<entry>
92149229
<literal><function>pg_database_size</function>(<parameter>oid</parameter>)</literal>
92159230
</entry>
9216-
<entry><type>int8</type></entry>
9217-
<entry>Calculates the total disk space used by the database with the specified OID</entry>
9231+
<entry><type>bigint</type></entry>
9232+
<entry>Total disk space used by the database with the specified OID</entry>
92189233
</row>
92199234
<row>
92209235
<entry>
92219236
<literal><function>pg_database_size</function>(<parameter>name</parameter>)</literal>
92229237
</entry>
9223-
<entry><type>int8</type></entry>
9224-
<entry>Calculates the total disk space used by the database with the specified name</entry>
9238+
<entry><type>bigint</type></entry>
9239+
<entry>Total disk space used by the database with the specified name</entry>
92259240
</row>
92269241
<row>
92279242
<entry>
92289243
<literal><function>pg_relation_size</function>(<parameter>oid</parameter>)</literal>
92299244
</entry>
9230-
<entry><type>int8</type></entry>
9231-
<entry>Calculates the disk space used by the table or index with the specified OID</entry>
9245+
<entry><type>bigint</type></entry>
9246+
<entry>Disk space used by the table or index with the specified OID</entry>
92329247
</row>
92339248
<row>
92349249
<entry>
92359250
<literal><function>pg_relation_size</function>(<parameter>text</parameter>)</literal>
92369251
</entry>
9237-
<entry><type>int8</type></entry>
9238-
<entry>Calculates the disk space used by the index or table with the specified name.
9239-
The name may be prefixed with a schema name if required</entry>
9252+
<entry><type>bigint</type></entry>
9253+
<entry>Disk space used by the table or index with the specified name.
9254+
The name may be qualified with a schema name</entry>
92409255
</row>
92419256
<row>
92429257
<entry>
92439258
<literal><function>pg_complete_relation_size</function>(<parameter>oid</parameter>)</literal>
92449259
</entry>
9245-
<entry><type>int8</type></entry>
9246-
<entry>Calculates the total disk space used by the table with the specified OID,
9260+
<entry><type>bigint</type></entry>
9261+
<entry>Total disk space used by the table with the specified OID,
92479262
including indexes and toasted data</entry>
92489263
</row>
92499264
<row>
92509265
<entry>
92519266
<literal><function>pg_complete_relation_size</function>(<parameter>text</parameter>)</literal>
92529267
</entry>
9253-
<entry><type>int8</type></entry>
9254-
<entry>Calculates the total disk space used by the table with the specified name,
9255-
including indexes and toasted data. The name may be prefixed with a schema name if
9256-
required</entry>
9268+
<entry><type>bigint</type></entry>
9269+
<entry>Total disk space used by the table with the specified name,
9270+
including indexes and toasted data.
9271+
The table name may be qualified with a schema name</entry>
92579272
</row>
92589273
<row> 10000 ;
92599274
<entry>
9260-
<literal><function>pg_size_pretty</function>(<parameter>int8</parameter>)</literal>
9275+
<literal><function>pg_size_pretty</function>(<parameter>bigint</parameter>)</literal>
92619276
</entry>
92629277
<entry><type>text</type></entry>
9263-
<entry>Formats the size value (in bytes) into a human readable format with size units </entry>
9278+
<entry>Converts a size in bytes into a human-readable format with size units</entry>
92649279
</row>
92659280
</tbody>
92669281
</tgroup>
92679282
</table>
92689283

92699284
<para>
9270-
<function>pg_tablespace_size</> and <function>pg_database_size</> accept an
9271-
oid or name of a tablespace or database, and return the disk space usage of the specified object.
9285+
<function>pg_column_size</> shows the space used to store any individual
9286+
data value.
92729287
</para>
92739288

9274-
<indexterm zone="functions-admin">
9275-
<primary>pg_relation_size</primary>
9276-
</indexterm>
92779289
<para>
9278-
<function>pg_relation_size</> accepts the oid or name of a table, index or
9290+
<function>pg_tablespace_size</> and <function>pg_database_size</> accept
9291+
the OID or name of a tablespace or database, and return the total disk
9292+
space used therein.
9293+
</para>
9294+
9295+
<para>
9296+
<function>pg_relation_size</> accepts the OID or name of a table, index or
92799297
toast table, and returns the size in bytes.
92809298
</para>
9299+
92819300
<para>
9282-
<function>pg_complete_relation_size</> accepts the oid or name of a table or
9283-
toast table, and returns the size in bytes of the data and all associated
9284-
indexes and toast tables.
9301+
<function>pg_complete_relation_size</> accepts the OID or name of a table
9302+
or toast table, and returns the size in bytes of the data and all
9303+
associated indexes and toast tables.
92859304
</para>
9305+
92869306
<para>
9287-
<function>pg_size_pretty</> can be used to format the size of the
9288-
database objects in a human readable way, using kB, MB, GB or TB as appropriate.
9307+
<function>pg_size_pretty</> can be used to format the result of one of
9308+
the other functions in a human-readable way, using kB, MB, GB or TB as
9309+
appropriate.
92899310
</para>
92909311

92919312
</sect1>

‎src/backend/access/heap/tuptoaster.c

Lines changed: 33 additions & 43 deletions
< 1CF5 /tr>
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $PostgreSQL: pgsql/src/backend/access/heap/tuptoaster.c,v 1.50 2005/07/06 19:02:52 momjian Exp $
11+
* $PostgreSQL: pgsql/src/backend/access/heap/tuptoaster.c,v 1.51 2005/08/02 16:11:57 tgl Exp $
1212
*
1313
*
1414
* INTERFACE ROUTINES
@@ -268,6 +268,38 @@ toast_raw_datum_size(Datum value)
268268
return result;
269269
}
270270

271+
/* ----------
272+
* toast_datum_size
273+
*
274+
* Return the physical storage size (possibly compressed) of a varlena datum
275+
* ----------
276+
*/
277+
Size
278+
toast_datum_size(Datum value)
279+
{
280+
varattrib *attr = (varattrib *) DatumGetPointer(value);
281+
Size result;
282+
283+
if (VARATT_IS_EXTERNAL(attr))
284+
{
285+
/*
286+
* Attribute is stored externally - return the extsize whether
287+
* compressed or not. We do not count the size of the toast
288+
* pointer ... should we?
289+
*/
290+
result = attr->va_content.va_external.va_extsize;
291+
}
292+
else
293+
{
294+
/*
295+
* Attribute is stored inline either compressed or not, just
296+
* calculate the size of the datum in either case.
297+
*/
298+
result = VARSIZE(attr);
299+
}
300+
return result;
301+
}
302+
271303

272304
/* ----------
273305
* toast_delete -
@@ -1436,45 +1468,3 @@ toast_fetch_datum_slice(varattrib *attr, int32 sliceoffset, int32 length)
14361468

14371469
return result;
14381470
}
1439-
1440-
/* ----------
1441-
* toast_datum_size
1442-
*
1443-
* Show the (possibly compressed) size of a datum
1444-
* ----------
1445-
*/
1446-
Size
1447-
toast_datum_size(Datum value)
1448-
{
1449-
1450-
varattrib *attr = (varattrib *) DatumGetPointer(value);
1451-
Size result;
1452-
1453-
if (VARATT_IS_EXTERNAL(attr))
1454-
{
1455-
/*
1456-
* Attribute is stored externally - If it is compressed too,
1457-
* then we need to get the external datum and calculate its size,
1458-
* otherwise we just use the external rawsize.
1459-
*/
1460-
if (VARATT_IS_COMPRESSED(attr))
1461-
{
1462-
varattrib *attrext = toast_fetch_datum(attr);
1463-
result = VARSIZE(attrext);
1464-
pfree(attrext);
1465-
}
1466-
else
1467-
result = attr->va_content.va_external.va_rawsize;
1468-
}
1469-
else
1470-
{
1471-
/*
1472-
* Attribute is stored inline either compressed or not, just
1473-
* calculate the size of the datum in either case.
1474-
*/
1475-
result = VARSIZE(attr);
1476-
}
1477-
1478-
return result;
1479-
1480-
}

‎src/backend/utils/adt/varlena.c

Lines changed: 30 additions & 19 deletions
D9E3
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $PostgreSQL: pgsql/src/backend/utils/adt/varlena.c,v 1.130 2005/07/29 03:17:55 momjian Exp $
11+
* $PostgreSQL: pgsql/src/backend/utils/adt/varlena.c,v 1.131 2005/08/02 16:11:57 tgl Exp $
1212
*
1313
*-------------------------------------------------------------------------
1414
*/
@@ -2574,38 +2574,49 @@ md5_bytea(PG_FUNCTION_ARGS)
25742574
}
25752575

25762576
/*
2577-
* Return the length of a datum, possibly compressed
2577+
* Return the size of a datum, possibly compressed
2578+
*
2579+
* Works on any data type
25782580
*/
25792581
Datum
25802582
pg_column_size(PG_FUNCTION_ARGS)
25812583
{
2582-
Datum value = PG_GETARG_DATUM(0);
2583-
int result;
2584+
Datum value = PG_GETARG_DATUM(0);
2585+
int32 result;
2586+
int typlen;
25842587

2585-
/* fn_extra stores the fixed column length, or -1 for varlena. */
2586-
if (fcinfo->flinfo->fn_extra == NULL) /* first call? */
2588+
/* On first call, get the input type's typlen, and save at *fn_extra */
2589+
if (fcinfo->flinfo->fn_extra == NULL)
25872590
{
2588-
/* On the first call lookup the datatype of the supplied argument */
2589-
Oid argtypeid = get_fn_expr_argtype(fcinfo->flinfo, 0);
2590-
int typlen = get_typlen(argtypeid);
2591+
/* Lookup the datatype of the supplied argument */
2592+
Oid argtypeid = get_fn_expr_argtype(fcinfo->flinfo, 0);
25912593

2592-
2593-
if (typlen == 0)
2594-
{
2595-
/* Oid not in pg_type, should never happen. */
2594+
typlen = get_typlen(argtypeid);
2595+
if (typlen == 0) /* should not happen */
25962596
elog(ERROR, "cache lookup failed for type %u", argtypeid);
2597-
}
25982597

25992598
fcinfo->flinfo->fn_extra = MemoryContextAlloc(fcinfo->flinfo->fn_mcxt,
26002599
sizeof(int));
2601-
*(int *)fcinfo->flinfo->fn_extra = typlen;
2600+
*((int *) fcinfo->flinfo->fn_extra) = typlen;
26022601
}
2602+
else
2603+
typlen = *((int *) fcinfo->flinfo->fn_extra);
26032604

2604-
if (*(int *)fcinfo->flinfo->fn_extra != -1)
2605-
PG_RETURN_INT32(*(int *)fcinfo->flinfo->fn_extra);
2605+
if (typlen == -1)
2606+
{
2607+
/* varlena type, possibly toasted */
2608+
result = toast_datum_size(value);
2609+
}
2610+
else if (typlen == -2)
2611+
{
2612+
/* cstring */
2613+
result = strlen(DatumGetCString(value)) + 1;
2614+
}
26062615
else
26072616
{
2608-
result = toast_datum_size(value) - VARHDRSZ;
2609-
PG_RETURN_INT32(result);
2617+
/* ordinary fixed-width type */
2618+
result = typlen;
26102619
}
2620+
2621+
PG_RETURN_INT32(result);
26112622
}

‎src/include/catalog/pg_proc.h

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -7,7 +7,7 @@
77
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
88
* Portions Copyright (c) 1994, Regents of the University of California
99
*
10-
* $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.379 2005/07/29 14:47:01 momjian Exp $
10+
* $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.380 2005/08/02 16:11:57 tgl Exp $
1111
*
1212
* NOTES
1313
* The script catalog/genbki.sh reads this file and generates .bki
@@ -3701,7 +3701,7 @@ DATA(insert OID = 2560 ( pg_postmaster_start_time PGNSP PGUID 12 f f t f s 0 11
37013701
DESCR("postmaster start time");
37023702

37033703
/* Column storage size */
3704-
DATA(insert OID = 1269 ( pg_column_size PGNSP PGUID 12 f f t f i 1 23 "2276" _null_ _null_ _null_ pg_column_size - _null_ ));
3704+
DATA(insert OID = 1269 ( pg_column_size PGNSP PGUID 12 f f t f s 1 23 "2276" _null_ _null_ _null_ pg_column_size - _null_ ));
37053705
DESCR("bytes required to store the value, perhaps with compression");
37063706

37073707
/* new functions for Y-direction rtree opclasses */

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