diff options
| author | Amit Kapila <akapila@postgresql.org> | 2020-07-20 08:48:26 +0530 |
|---|---|---|
| committer | Amit Kapila <akapila@postgresql.org> | 2020-07-20 08:48:26 +0530 |
| commit | 0bead9af484c1d0a67e690fda47011addaa5bc9d (patch) | |
| tree | 246db2163552a439ac1b7903fd36cb02e73cea3c /src/backend/access/transam/xlogreader.c | |
| parent | d05b172a760e0ccb3008a2144f96053720000b12 (diff) | |
Immediately WAL-log subtransaction and top-level XID association.
The logical decoding infrastructure needs to know which top-level
transaction the subxact belongs to, in order to decode all the
changes. Until now that might be delayed until commit, due to the
caching (GPROC_MAX_CACHED_SUBXIDS), preventing features requiring
incremental decoding.
So we also write the assignment info into WAL immediately, as part
of the next WAL record (to minimize overhead) only when wal_level=logical.
We can not remove the existing XLOG_XACT_ASSIGNMENT WAL as that is
required for avoiding overflow in the hot standby snapshot.
Bump XLOG_PAGE_MAGIC, since this introduces XLR_BLOCK_ID_TOPLEVEL_XID.
Author: Tomas Vondra, Dilip Kumar, Amit Kapila
Reviewed-by: Amit Kapila
Tested-by: Neha Sharma and Mahendra Singh Thalor
Discussion: https://postgr.es/m/688b0b7f-2f6c-d827-c27b-216a8e3ea700@2ndquadrant.com
Diffstat (limited to 'src/backend/access/transam/xlogreader.c')
| -rw-r--r-- | src/backend/access/transam/xlogreader.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c index cb76be4f469..a757baccfc5 100644 --- a/src/backend/access/transam/xlogreader.c +++ b/src/backend/access/transam/xlogreader.c @@ -1197,6 +1197,7 @@ DecodeXLogRecord(XLogReaderState *state, XLogRecord *record, char **errormsg) state->decoded_record = record; state->record_origin = InvalidRepOriginId; + state->toplevel_xid = InvalidTransactionId; ptr = (char *) record; ptr += SizeOfXLogRecord; @@ -1235,6 +1236,10 @@ DecodeXLogRecord(XLogReaderState *state, XLogRecord *record, char **errormsg) { COPY_HEADER_FIELD(&state->record_origin, sizeof(RepOriginId)); } + else if (block_id == XLR_BLOCK_ID_TOPLEVEL_XID) + { + COPY_HEADER_FIELD(&state->toplevel_xid, sizeof(TransactionId)); + } else if (block_id <= XLR_MAX_BLOCK_ID) { /* XLogRecordBlockHeader */ |