diff options
| author | Fujii Masao | 2019-11-21 12:10:37 +0000 |
|---|---|---|
| committer | Fujii Masao | 2019-11-21 12:10:37 +0000 |
| commit | e6d8069522c8bde8239dd1fedfb4984efa4b3a1a (patch) | |
| tree | b0d38edfd892bdd52f3086616c36d1bce5d350ab /src/include/commands | |
| parent | 30840c92ac0c4073fb7bc8222317630571b8cf25 (diff) | |
Make DROP DATABASE command generate less WAL records.
Previously DROP DATABASE generated as many XLOG_DBASE_DROP WAL records
as the number of tablespaces that the database to drop uses. This caused
the scans of shared_buffers as many times as the number of the tablespaces
during recovery because WAL replay of one XLOG_DBASE_DROP record needs
that full scan. This could make the recovery time longer especially
when shared_buffers is large.
This commit changes DROP DATABASE so that it generates only one
XLOG_DBASE_DROP record, and registers the information of all the tablespaces
into it. Then, WAL replay of XLOG_DBASE_DROP record needs full scan of
shared_buffers only once, and which may improve the recovery performance.
Author: Fujii Masao
Reviewed-by: Kirk Jamison, Simon Riggs
Discussion: https://postgr.es/m/CAHGQGwF8YwNH0ZaL+2wjZPkj+ji9UhC+Z4ScnG97WKtVY5L9iw@mail.gmail.com
Diffstat (limited to 'src/include/commands')
| -rw-r--r-- | src/include/commands/dbcommands_xlog.h | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/src/include/commands/dbcommands_xlog.h b/src/include/commands/dbcommands_xlog.h index 46be8a615ac..4e8a442c89f 100644 --- a/src/include/commands/dbcommands_xlog.h +++ b/src/include/commands/dbcommands_xlog.h @@ -32,10 +32,11 @@ typedef struct xl_dbase_create_rec typedef struct xl_dbase_drop_rec { - /* Records dropping of a single subdirectory incl. contents */ Oid db_id; - Oid tablespace_id; + int ntablespaces; /* number of tablespace IDs */ + Oid tablespace_ids[FLEXIBLE_ARRAY_MEMBER]; } xl_dbase_drop_rec; +#define MinSizeOfDbaseDropRec offsetof(xl_dbase_drop_rec, tablespace_ids) extern void dbase_redo(XLogReaderState *rptr); extern void dbase_desc(StringInfo buf, XLogReaderState *rptr); |