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Revert "Logical decoding of sequences"

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This reverts a sequence of commits, implementing features related to
logical decoding and replication of sequences:

 - 0da92dc530
 - 80901b3291
 - b779d7d8fd
 - d5ed9da41d
 - a180c2b34d
 - 75b1521dae
 - 2d2232933b
 - 002c9dd97a
 - 05843b1aa4

The implementation has issues, mostly due to combining transactional and
non-transactional behavior of sequences. It's not clear how this could
be fixed, but it'll require reworking significant part of the patch.

Discussion: https://postgr.es/m/95345a19-d508-63d1-860a-f5c2f41e8d40@enterprisedb.com
This commit is contained in:
Tomas Vondra
2022-04-07 18:13:13 +02:00
parent d7ab2a9a3c
commit 2c7ea57e56
73 changed files with 605 additions and 4762 deletions
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65
doc/src/sgml/logicaldecoding.sgml
View File

@@ -458,7 +458,6 @@ typedef struct OutputPluginCallbacks
LogicalDecodeTruncateCB truncate_cb;
LogicalDecodeCommitCB commit_cb;
LogicalDecodeMessageCB message_cb;
LogicalDecodeSequenceCB sequence_cb;
LogicalDecodeFilterByOriginCB filter_by_origin_cb;
LogicalDecodeShutdownCB shutdown_cb;
LogicalDecodeFilterPrepareCB filter_prepare_cb;
@@ -473,7 +472,6 @@ typedef struct OutputPluginCallbacks
LogicalDecodeStreamCommitCB stream_commit_cb;
LogicalDecodeStreamChangeCB stream_change_cb;
LogicalDecodeStreamMessageCB stream_message_cb;
LogicalDecodeStreamSequenceCB stream_sequence_cb;
LogicalDecodeStreamTruncateCB stream_truncate_cb;
} OutputPluginCallbacks;
@@ -483,11 +481,9 @@ typedef void (*LogicalOutputPluginInit) (struct OutputPluginCallbacks *cb);
and <function>commit_cb</function> callbacks are required,
while <function>startup_cb</function>,
<function>filter_by_origin_cb</function>, <function>truncate_cb</function>,
<function>sequence_cb</function>, and <function>shutdown_cb</function> are
optional. If <function>truncate_cb</function> is not set but a
and <function>shutdown_cb</function> are optional.
If <function>truncate_cb</function> is not set but a
<command>TRUNCATE</command> is to be decoded, the action will be ignored.
Similarly, if <function>sequence_cb</function> is not set and a sequence
change is to be decoded, the action will be ignored.
</para>
<para>
@@ -496,8 +492,7 @@ typedef void (*LogicalOutputPluginInit) (struct OutputPluginCallbacks *cb);
<function>stream_stop_cb</function>, <function>stream_abort_cb</function>,
<function>stream_commit_cb</function>, <function>stream_change_cb</function>,
and <function>stream_prepare_cb</function>
are required, while <function>stream_message_cb</function>,
<function>stream_sequence_cb</function>, and
are required, while <function>stream_message_cb</function> and
<function>stream_truncate_cb</function> are optional.
</para>
@@ -813,35 +808,6 @@ typedef void (*LogicalDecodeMessageCB) (struct LogicalDecodingContext *ctx,
</para>
</sect3>
<sect3 id="logicaldecoding-output-plugin-sequence">
<title>Sequence Callback</title>
<para>
The optional <function>sequence_cb</function> callback is called for
actions that update a sequence value.
<programlisting>
typedef void (*LogicalDecodeSequenceCB) (struct LogicalDecodingContext *ctx,
ReorderBufferTXN *txn,
XLogRecPtr sequence_lsn,
Relation rel,
bool transactional,
int64 last_value,
int64 log_cnt,
bool is_called);
</programlisting>
The <parameter>txn</parameter> parameter contains meta information about
the transaction the sequence change is part of. Note however that for
non-transactional increments, the transaction may be either NULL or not
NULL, depending on if the transaction already has an XID assigned.
The <parameter>sequence_lsn</parameter> has the WAL location of the
sequence update. <parameter>transactional</parameter> says if the
sequence has to be replayed as part of the transaction or directly.
The <parameter>last_value</parameter>, <parameter>log_cnt</parameter> and
<parameter>is_called</parameter> parameters describe the sequence change.
</para>
</sect3>
<sect3 id="logicaldecoding-output-plugin-filter-prepare">
<title>Prepare Filter Callback</title>
@@ -1051,26 +1017,6 @@ typedef void (*LogicalDecodeStreamMessageCB) (struct LogicalDecodingContext *ctx
</para>
</sect3>
<sect3 id="logicaldecoding-output-plugin-stream-sequence">
<title>Stream Sequence Callback</title>
<para>
The optional <function>stream_sequence_cb</function> callback is called
for actions that change a sequence in a block of streamed changes
(demarcated by <function>stream_start_cb</function> and
<function>stream_stop_cb</function> calls).
<programlisting>
typedef void (*LogicalDecodeStreamSequenceCB) (struct LogicalDecodingContext *ctx,
ReorderBufferTXN *txn,
XLogRecPtr sequence_lsn,
Relation rel,
bool transactional,
int64 last_value,
int64 log_cnt,
bool is_called);
</programlisting>
</para>
</sect3>
<sect3 id="logicaldecoding-output-plugin-stream-truncate">
<title>Stream Truncate Callback</title>
<para>
@@ -1251,9 +1197,8 @@ OutputPluginWrite(ctx, true);
in-progress transactions. There are multiple required streaming callbacks
(<function>stream_start_cb</function>, <function>stream_stop_cb</function>,
<function>stream_abort_cb</function>, <function>stream_commit_cb</function>
and <function>stream_change_cb</function>) and multiple optional callbacks
(<function>stream_message_cb</function>, <function>stream_sequence_cb</function>,
and <function>stream_truncate_cb</function>).
and <function>stream_change_cb</function>) and two optional callbacks
(<function>stream_message_cb</function> and <function>stream_truncate_cb</function>).
Also, if streaming of two-phase commands is to be supported, then additional
callbacks must be provided. (See <xref linkend="logicaldecoding-two-phase-commits"/>
for details).