diff options
author | Heikki Linnakangas | 2015-01-16 16:16:40 +0000 |
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committer | Heikki Linnakangas | 2015-01-16 16:16:40 +0000 |
commit | c9ab1f957a7f1836e29aca460c25f28a96b2b2af (patch) | |
tree | 7a3f685cb50b7656a8dbb30a4a292e9a79882219 | |
parent | 7351ca899eaf5aba086876d54d01df38f469ec18 (diff) |
Use standard top-level sections in reference page.pg_rewind
-rw-r--r-- | doc/src/sgml/ref/pg_rewind.sgml | 90 |
1 files changed, 45 insertions, 45 deletions
diff --git a/doc/src/sgml/ref/pg_rewind.sgml b/doc/src/sgml/ref/pg_rewind.sgml index 686cf2a0e2..4458ae0d56 100644 --- a/doc/src/sgml/ref/pg_rewind.sgml +++ b/doc/src/sgml/ref/pg_rewind.sgml @@ -107,9 +107,9 @@ PostgreSQL documentation <term><option>--source-pgdata</option></term> <listitem> <para> - Specifies a source data directory to synchronize the target with. - When <option>--source-pgdata</> is used, the source server must be - cleanly shut down. + Specifies path to the data directory of the source server, to + synchronize the target with. When <option>--source-pgdata</> is + used, the source server must be cleanly shut down. </para> </listitem> </varlistentry> @@ -183,54 +183,54 @@ PostgreSQL documentation </refsect1> <refsect1> - <title>Theory of operation</title> - - <para> - The basic idea is to copy everything from the new cluster to the old - cluster, except for the blocks that we know to be the same. - </para> - - <procedure> - <step> - <para> - Scan the WAL log of the old cluster, starting from the last checkpoint - before the point where the new cluster's timeline history forked off - from the old cluster. For each WAL record, make a note of the data - blocks that were touched. This yields a list of all the data blocks - that were changed in the old cluster, after the new cluster forked off. - </para> - </step> - <step> - <para> - Copy all those changed blocks from the new cluster to the old cluster. - </para> - </step> - <step> - <para> - Copy all other files like clog, conf files etc. from the new cluster - to old cluster. Everything except the relation files. - </para> - </step> - <step> - <para> - Apply the WAL from the new cluster, starting from the checkpoint - created at failover. (Strictly speaking, <application>pg_rewind</> - doesn't apply the WAL, it just creates a backup label file indicating - that when <productname>PostgreSQL</> is started, it will start replay - from that checkpoint and apply all the required WAL.) - </para> - </step> - </procedure> - </refsect1> - - <refsect1> - <title>Restrictions</title> + <title>Notes</title> <para> <application>pg_rewind</> requires that the <varname>wal_log_hints</> option is enabled in <filename>postgresql.conf</>, or that data checksums were enabled when the cluster was initialized with <application>initdb</>. </para> + + <refsect2> + <title>How it works</title> + + <para> + The basic idea is to copy everything from the new cluster to the old + cluster, except for the blocks that we know to be the same. + </para> + + <procedure> + <step> + <para> + Scan the WAL log of the old cluster, starting from the last checkpoint + before the point where the new cluster's timeline history forked off + from the old cluster. For each WAL record, make a note of the data + blocks that were touched. This yields a list of all the data blocks + that were changed in the old cluster, after the new cluster forked off. + </para> + </step> + <step> + <para> + Copy all those changed blocks from the new cluster to the old cluster. + </para> + </step> + <step> + <para> + Copy all other files like clog, conf files etc. from the new cluster + to old cluster. Everything except the relation files. + </para> + </step> + <step> + <para> + Apply the WAL from the new cluster, starting from the checkpoint + created at failover. (Strictly speaking, <application>pg_rewind</> + doesn't apply the WAL, it just creates a backup label file indicating + that when <productname>PostgreSQL</> is started, it will start replay + from that checkpoint and apply all the required WAL.) + </para> + </step> + </procedure> + </refsect2> </refsect1> </refentry> |