From 5e45211a64149b3c659b90ff2de6fa982a5a93ed Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 4 May 2024 14:17:33 +0200 Subject: Adding upstream version 15.5. Signed-off-by: Daniel Baumann --- doc/src/sgml/html/test-decoding.html | 48 ++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 doc/src/sgml/html/test-decoding.html (limited to 'doc/src/sgml/html/test-decoding.html') diff --git a/doc/src/sgml/html/test-decoding.html b/doc/src/sgml/html/test-decoding.html new file mode 100644 index 0000000..6734bbb --- /dev/null +++ b/doc/src/sgml/html/test-decoding.html @@ -0,0 +1,48 @@ + +F.45. test_decoding
F.45. test_decoding
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F.45. test_decoding

+ test_decoding is an example of a logical decoding + output plugin. It doesn't do anything especially useful, but can serve as + a starting point for developing your own output plugin. +

+ test_decoding receives WAL through the logical decoding + mechanism and decodes it into text representations of the operations + performed. +

+ Typical output from this plugin, used over the SQL logical decoding + interface, might be: + +

+postgres=# SELECT * FROM pg_logical_slot_get_changes('test_slot', NULL, NULL, 'include-xids', '0');
+   lsn     | xid |                       data
+-----------+-----+--------------------------------------------------
+ 0/16D30F8 | 691 | BEGIN
+ 0/16D32A0 | 691 | table public.data: INSERT: id[int4]:2 data[text]:'arg'
+ 0/16D32A0 | 691 | table public.data: INSERT: id[int4]:3 data[text]:'demo'
+ 0/16D32A0 | 691 | COMMIT
+ 0/16D32D8 | 692 | BEGIN
+ 0/16D3398 | 692 | table public.data: DELETE: id[int4]:2
+ 0/16D3398 | 692 | table public.data: DELETE: id[int4]:3
+ 0/16D3398 | 692 | COMMIT
+(8 rows)
+

+

+ We can also get the changes of the in-progress transaction, and the typical + output might be: + +

+postgres[33712]=#* SELECT * FROM pg_logical_slot_get_changes('test_slot', NULL, NULL, 'stream-changes', '1');
+    lsn    | xid |                       data
+-----------+-----+--------------------------------------------------
+ 0/16B21F8 | 503 | opening a streamed block for transaction TXN 503
+ 0/16B21F8 | 503 | streaming change for TXN 503
+ 0/16B2300 | 503 | streaming change for TXN 503
+ 0/16B2408 | 503 | streaming change for TXN 503
+ 0/16BEBA0 | 503 | closing a streamed block for transaction TXN 503
+ 0/16B21F8 | 503 | opening a streamed block for transaction TXN 503
+ 0/16BECA8 | 503 | streaming change for TXN 503
+ 0/16BEDB0 | 503 | streaming change for TXN 503
+ 0/16BEEB8 | 503 | streaming change for TXN 503
+ 0/16BEBA0 | 503 | closing a streamed block for transaction TXN 503
+(10 rows)
+

+

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