On 23-12-2011 12:05, Tom Lane wrote:
> I too think a datatype is overkill, if we're only planning on providing
> one function. Just emit the values as numeric and have done.
>
Here it is. Output changed to numeric. While the output was int8 I could use
pg_size_pretty but now I couldn't. I attached another patch that implements
pg_size_pretty(numeric).
--
Euler Taveira de Oliveira - Timbira http://www.timbira.com.br/
PostgreSQL: Consultoria, Desenvolvimento, Suporte 24x7 e Treinamento
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 48631cc..04bc24d 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -14378,6 +14378,9 @@ SELECT set_config('log_statement_stats', 'off', false);
<indexterm>
<primary>pg_xlogfile_name_offset</primary>
</indexterm>
+ <indexterm>
+ <primary>pg_xlog_location_diff</primary>
+ </indexterm>
<para>
The functions shown in <xref
@@ -14450,6 +14453,13 @@ SELECT set_config('log_statement_stats', 'off', false);
<entry><type>text</>, <type>integer</></entry>
<entry>Convert transaction log location string to file name and decimal byte offset within file</entry>
</row>
+ <row>
+ <entry>
+ <literal><function>pg_xlog_location_diff(<parameter>location</> <type>text</>, <parameter>location</> <type>text</>)</function></literal>
+ </entry>
+ <entry><type>numeric</></entry>
+ <entry>Calculate the difference between two transaction log locations</entry>
+ </row>
</tbody>
</tgroup>
</table>
@@ -14543,6 +14553,13 @@ postgres=# SELECT * FROM pg_xlogfile_name_offset(pg_stop_backup());
</para>
<para>
+ <function>pg_xlog_location_diff</> calculates the difference in bytes
+ between two transaction log locations. It can be used with
+ <structname>pg_stat_replication</structname> or some functions shown in
+ <xref linkend="functions-admin-backup-table"> to get the replication lag.
+ </para>
+
+ <para>
For details about proper usage of these functions, see
<xref linkend="continuous-archiving">.
</para>
diff --git a/src/backend/access/transam/xlogfuncs.c b/src/backend/access/transam/xlogfuncs.c
index 2e10d4d..e03c5e8 100644
--- a/src/backend/access/transam/xlogfuncs.c
+++ b/src/backend/access/transam/xlogfuncs.c
@@ -26,6 +26,7 @@
#include "replication/walreceiver.h"
#include "storage/smgr.h"
#include "utils/builtins.h"
+#include "utils/numeric.h"
#include "utils/guc.h"
#include "utils/timestamp.h"
@@ -465,3 +466,84 @@ pg_is_in_recovery(PG_FUNCTION_ARGS)
{
PG_RETURN_BOOL(RecoveryInProgress());
}
+
+static void
+validate_xlog_location(char *str)
+{
+#define MAXLSNCOMPONENT 8
+
+ int len1, len2;
+
+ len1 = strspn(str, "0123456789abcdefABCDEF");
+ if (len1 < 1 || len1 > MAXLSNCOMPONENT || str[len1] != '/')
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+ errmsg("invalid input syntax for transaction log location: \"%s\"", str)));
+ len2 = strspn(str + len1 + 1, "0123456789abcdefABCDEF");
+ if (len2 < 1 || len2 > MAXLSNCOMPONENT || str[len1 + 1 + len2] != '\0')
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+ errmsg("invalid input syntax for transaction log location: \"%s\"", str)));
+}
+
+/*
+ * Compute the difference in bytes between two WAL locations.
+ */
+Datum
+pg_xlog_location_diff(PG_FUNCTION_ARGS)
+{
+ text *location1 = PG_GETARG_TEXT_P(0);
+ text *location2 = PG_GETARG_TEXT_P(1);
+ char *str1, *str2;
+ uint64 xlogid1, xrecoff1;
+ uint64 xlogid2, xrecoff2;
+ Numeric result;
+
+ /*
+ * Read and parse input
+ */
+ str1 = text_to_cstring(location1);
+ str2 = text_to_cstring(location2);
+
+ validate_xlog_location(str1);
+ validate_xlog_location(str2);
+
+ if (sscanf(str1, "%8lX/%8lX", &xlogid1, &xrecoff1) != 2)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("could not parse transaction log location \"%s\"", str1)));
+ if (sscanf(str2, "%8lX/%8lX", &xlogid2, &xrecoff2) != 2)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("could not parse transaction log location \"%s\"", str2)));
+
+ /*
+ * Sanity check
+ */
+ if (xrecoff1 > XLogFileSize)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("xrecoff \"%lX\" is out of valid range, 0..%X", xrecoff1, XLogFileSize)));
+ if (xrecoff2 > XLogFileSize)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("xrecoff \"%lX\" is out of valid range, 0..%X", xrecoff2, XLogFileSize)));
+
+ /*
+ * result = XLogFileSize * (xlogid1 - xlogid2) + xrecoff1 - xrecoff2
+ */
+ result = DatumGetNumeric(DirectFunctionCall2(numeric_sub,
+ DirectFunctionCall1(int8_numeric, Int64GetDatum(xlogid1)),
+ DirectFunctionCall1(int8_numeric, Int64GetDatum(xlogid2))));
+ result = DatumGetNumeric(DirectFunctionCall2(numeric_mul,
+ DirectFunctionCall1(int8_numeric, Int64GetDatum(XLogFileSize)),
+ NumericGetDatum(result)));
+ result = DatumGetNumeric(DirectFunctionCall2(numeric_add,
+ NumericGetDatum(result),
+ DirectFunctionCall1(int8_numeric, Int64GetDatum(xrecoff1))));
+ result = DatumGetNumeric(DirectFunctionCall2(numeric_sub,
+ NumericGetDatum(result),
+ DirectFunctionCall1(int8_numeric, Int64GetDatum(xrecoff2))));
+
+ PG_RETURN_NUMERIC(result);
+}
diff --git a/src/include/access/xlog_internal.h b/src/include/access/xlog_internal.h
index db6380f..fa45aa1 100644
--- a/src/include/access/xlog_internal.h
+++ b/src/include/access/xlog_internal.h
@@ -281,5 +281,6 @@ extern Datum pg_is_in_recovery(PG_FUNCTION_ARGS);
extern Datum pg_xlog_replay_pause(PG_FUNCTION_ARGS);
extern Datum pg_xlog_replay_resume(PG_FUNCTION_ARGS);
extern Datum pg_is_xlog_replay_paused(PG_FUNCTION_ARGS);
+extern Datum pg_xlog_location_diff(PG_FUNCTION_ARGS);
#endif /* XLOG_INTERNAL_H */
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index b6ac195..9940658 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -2902,6 +2902,8 @@ DATA(insert OID = 2850 ( pg_xlogfile_name_offset PGNSP PGUID 12 1 0 0 0 f f f t
DESCR("xlog filename and byte offset, given an xlog location");
DATA(insert OID = 2851 ( pg_xlogfile_name PGNSP PGUID 12 1 0 0 0 f f f t f i 1 0 25 "25" _null_ _null_ _null_ _null_ pg_xlogfile_name _null_ _null_ _null_ ));
DESCR("xlog filename, given an xlog location");
+DATA(insert OID = 3150 ( pg_xlog_location_diff PGNSP PGUID 12 1 0 0 0 f f f t f i 2 0 1700 "25 25" _null_ _null_ _null_ _null_ pg_xlog_location_diff _null_ _null_ _null_ ));
+DESCR("difference in bytes, given two xlog locations");
DATA(insert OID = 3809 ( pg_export_snapshot PGNSP PGUID 12 1 0 0 0 f f f t f v 0 0 25 "" _null_ _null_ _null_ _null_ pg_export_snapshot _null_ _null_ _null_ ));
DESCR("export a snapshot");
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 48631cc..eff2b0e 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -14881,6 +14881,13 @@ postgres=# SELECT * FROM pg_xlogfile_name_offset(pg_stop_backup());
</row>
<row>
<entry>
+ <literal><function>pg_size_pretty(<type>numeric</type>)</function></literal>
+ </entry>
+ <entry><type>text</type></entry>
+ <entry>Converts a size in bytes into a human-readable format with size units</entry>
+ </row>
+ <row>
+ <entry>
<literal><function>pg_table_size(<type>regclass</type>)</function></literal>
</entry>
<entry><type>bigint</type></entry>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 26a8c01..494ce27 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -24,6 +24,7 @@
#include "storage/fd.h"
#include "utils/acl.h"
#include "utils/builtins.h"
+#include "utils/numeric.h"
#include "utils/rel.h"
#include "utils/relmapper.h"
#include "utils/syscache.h"
@@ -550,6 +551,93 @@ pg_size_pretty(PG_FUNCTION_ARGS)
PG_RETURN_TEXT_P(cstring_to_text(buf));
}
+Datum
+pg_size_pretty_num(PG_FUNCTION_ARGS)
+{
+ Numeric size = PG_GETARG_NUMERIC(0);
+ Numeric limit, limit2;
+
+ char *buf, *result;
+
+ limit = DatumGetNumeric(DirectFunctionCall1(int8_numeric, Int64GetDatum((int64) (10 * 1024))));
+ limit2 = DatumGetNumeric(DirectFunctionCall1(int8_numeric, Int64GetDatum((int64) (10 * 1024 * 2 - 1))));
+
+ if (DatumGetBool(DirectFunctionCall2(numeric_lt, NumericGetDatum(size), NumericGetDatum(limit))))
+ {
+ buf = DatumGetCString(DirectFunctionCall1(numeric_out, NumericGetDatum(size)));
+ result = strcat(buf, " bytes");
+ }
+ else
+ {
+ Numeric arg2;
+
+ /* keep one extra bit for rounding */
+ /* size >>= 9 */
+ arg2 = DatumGetNumeric(DirectFunctionCall1(int8_numeric, Int64GetDatum((int64) pow(2, 9))));
+ size = DatumGetNumeric(DirectFunctionCall2(numeric_div_trunc, NumericGetDatum(size), NumericGetDatum(arg2)));
+
+ if (DatumGetBool(DirectFunctionCall2(numeric_lt, NumericGetDatum(size), NumericGetDatum(limit2))))
+ {
+ /* size = (size + 1) / 2 */
+ size = DatumGetNumeric(DirectFunctionCall2(numeric_add, NumericGetDatum(size),
+ DirectFunctionCall1(int8_numeric, Int64GetDatum(1))));
+ size = DatumGetNumeric(DirectFunctionCall2(numeric_div_trunc, NumericGetDatum(size),
+ DirectFunctionCall1(int8_numeric, Int64GetDatum(2))));
+ buf = DatumGetCString(DirectFunctionCall1(numeric_out, NumericGetDatum(size)));
+ result = strcat(buf, " kB");
+ }
+ else
+ {
+ Numeric arg3;
+
+ /* size >>= 10 */
+ arg3 = DatumGetNumeric(DirectFunctionCall1(int8_numeric, Int64GetDatum((int64) pow(2, 10))));
+ size = DatumGetNumeric(DirectFunctionCall2(numeric_div_trunc, NumericGetDatum(size), NumericGetDatum(arg3)));
+
+ if (DatumGetBool(DirectFunctionCall2(numeric_lt, NumericGetDatum(size), NumericGetDatum(limit2))))
+ {
+ /* size = (size + 1) / 2 */
+ size = DatumGetNumeric(DirectFunctionCall2(numeric_add, NumericGetDatum(size),
+ DirectFunctionCall1(int8_numeric, Int64GetDatum(1))));
+ size = DatumGetNumeric(DirectFunctionCall2(numeric_div_trunc, NumericGetDatum(size),
+ DirectFunctionCall1(int8_numeric, Int64GetDatum(2))));
+ buf = DatumGetCString(DirectFunctionCall1(numeric_out, NumericGetDatum(size)));
+ result = strcat(buf, " MB");
+ }
+ else
+ {
+ /* size >>= 10 */
+ size = DatumGetNumeric(DirectFunctionCall2(numeric_div_trunc, NumericGetDatum(size), NumericGetDatum(arg3)));
+
+ if (DatumGetBool(DirectFunctionCall2(numeric_lt, NumericGetDatum(size), NumericGetDatum(limit2))))
+ {
+ /* size = (size + 1) / 2 */
+ size = DatumGetNumeric(DirectFunctionCall2(numeric_add, NumericGetDatum(size),
+ DirectFunctionCall1(int8_numeric, Int64GetDatum(1))));
+ size = DatumGetNumeric(DirectFunctionCall2(numeric_div_trunc, NumericGetDatum(size),
+ DirectFunctionCall1(int8_numeric, Int64GetDatum(2))));
+ buf = DatumGetCString(DirectFunctionCall1(numeric_out, NumericGetDatum(size)));
+ result = strcat(buf, " GB");
+ }
+ else
+ {
+ /* size = (size + 1) / 2 */
+ size = DatumGetNumeric(DirectFunctionCall2(numeric_div_trunc, NumericGetDatum(size), NumericGetDatum(arg3)));
+ size = DatumGetNumeric(DirectFunctionCall2(numeric_add, NumericGetDatum(size),
+ DirectFunctionCall1(int8_numeric, Int64GetDatum(1))));
+ size = DatumGetNumeric(DirectFunctionCall2(numeric_div_trunc, NumericGetDatum(size),
+ DirectFunctionCall1(int8_numeric, Int64GetDatum(2))));
+
+ buf = DatumGetCString(DirectFunctionCall1(numeric_out, NumericGetDatum(size)));
+ result = strcat(buf, " TB");
+ }
+ }
+ }
+ }
+
+ PG_RETURN_TEXT_P(cstring_to_text(result));
+}
+
/*
* Get the filenode of a relation
*
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index b6ac195..0d8d486 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -3364,6 +3364,7 @@ DESCR("disk space usage for the specified fork of a table or index");
DATA(insert OID = 2286 ( pg_total_relation_size PGNSP PGUID 12 1 0 0 0 f f f t f v 1 0 20 "2205" _null_ _null_ _null_ _null_ pg_total_relation_size _null_ _null_ _null_ ));
DESCR("total disk space usage for the specified table and associated indexes");
DATA(insert OID = 2288 ( pg_size_pretty PGNSP PGUID 12 1 0 0 0 f f f t f v 1 0 25 "20" _null_ _null_ _null_ _null_ pg_size_pretty _null_ _null_ _null_ ));
+DATA(insert OID = 3151 ( pg_size_pretty PGNSP PGUID 12 1 0 0 0 f f f t f v 1 0 25 "1700" _null_ _null_ _null_ _null_ pg_size_pretty_num _null_ _null_ _null_ ));
DESCR("convert a long int to a human readable text using size units");
DATA(insert OID = 2997 ( pg_table_size PGNSP PGUID 12 1 0 0 0 f f f t f v 1 0 20 "2205" _null_ _null_ _null_ _null_ pg_table_size _null_ _null_ _null_ ));
DESCR("disk space usage for the specified table, including TOAST, free space and visibility map");
diff --git a/src/include/utils/builtins.h b/src/include/utils/builtins.h
index 68179d5..3d07f29 100644
--- a/src/include/utils/builtins.h
+++ b/src/include/utils/builtins.h
@@ -453,6 +453,7 @@ extern Datum pg_database_size_name(PG_FUNCTION_ARGS);
extern Datum pg_relation_size(PG_FUNCTION_ARGS);
extern Datum pg_total_relation_size(PG_FUNCTION_ARGS);
extern Datum pg_size_pretty(PG_FUNCTION_ARGS);
+extern Datum pg_size_pretty_num(PG_FUNCTION_ARGS);
extern Datum pg_table_size(PG_FUNCTION_ARGS);
extern Datum pg_indexes_size(PG_FUNCTION_ARGS);
extern Datum pg_relation_filenode(PG_FUNCTION_ARGS);
--
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