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author | Michael Paquier | 2023-01-23 04:55:18 +0000 |
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committer | Michael Paquier | 2023-01-23 04:55:18 +0000 |
commit | c31cf1c03d01ce86f20bef8c980fe56a257b3b4b (patch) | |
tree | 171926cd166100130f6e7e1c0f799450db60ec20 /doc | |
parent | 16fd03e956540d1b47b743f6a84f37c54ac93dd4 (diff) |
pg_walinspect: Add pg_get_wal_fpi_info()
This function is able to extract the full page images from a range of
records, specified as of input arguments start_lsn and end_lsn. Like
the other functions of this module, an error is returned if using LSNs
that do not reflect real system values. All the FPIs stored in a single
record are extracted.
The module's version is bumped to 1.1.
Author: Bharath Rupireddy
Reviewed-by: Bertrand Drouvot
Discussion: https://postgr.es/m/CALj2ACVCcvzd7WiWvD=6_7NBvVB_r6G0EGSxL4F8vosAi6Se4g@mail.gmail.com
Diffstat (limited to 'doc')
-rw-r--r-- | doc/src/sgml/pgwalinspect.sgml | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/doc/src/sgml/pgwalinspect.sgml b/doc/src/sgml/pgwalinspect.sgml index 119e162e60..22677e54f2 100644 --- a/doc/src/sgml/pgwalinspect.sgml +++ b/doc/src/sgml/pgwalinspect.sgml @@ -188,6 +188,38 @@ combined_size_percentage | 2.8634072910530795 </listitem> </varlistentry> + <varlistentry> + <term> + <function>pg_get_wal_fpi_info(start_lsn pg_lsn, end_lsn pg_lsn) returns setof record</function> + </term> + + <listitem> + <para> + Gets a copy of full page images as <type>bytea</type> values (after + applying decompression when necessary) and their information associated + with all the valid WAL records between + <replaceable>start_lsn</replaceable> and + <replaceable>end_lsn</replaceable>. Returns one row per full page image. + If <replaceable>start_lsn</replaceable> or + <replaceable>end_lsn</replaceable> are not yet available, the function + will raise an error. For example: +<screen> +postgres=# SELECT lsn, reltablespace, reldatabase, relfilenode, relblocknumber, + forkname, substring(fpi for 24) as fpi_trimmed + FROM pg_get_wal_fpi_info('0/1801690', '0/1825C60'); +-[ RECORD 1 ]--+--------------------------------------------------- +lsn | 0/1807E20 +reltablespace | 1663 +reldatabase | 5 +relfilenode | 16396 +relblocknumber | 43 +forkname | main +fpi_trimmed | \x00000000b89e660100000000a003c0030020042000000000 +</screen> + </para> + </listitem> + </varlistentry> + </variablelist> </sect2> |