From 2c3b25373496b4a1856942c72770b3ef1ae10413 Mon Sep 17 00:00:00 2001 From: Melanie Plageman Date: Tue, 5 Dec 2023 07:29:39 -0500 Subject: [PATCH v2 01/10] Record LSN at postmaster startup The insert_lsn at postmaster startup can be used along with PgStartTime as seed values for a timeline mapping LSNs to time. This allows rate calculation after inserting even a single point. This is WIP, I'm not sure if I did this in the right place or if it should be a separate commit from the one adding the LSNTimeline since it doesn't make much sense on its own. --- src/backend/access/transam/xlog.c | 2 ++ src/backend/postmaster/postmaster.c | 1 + src/include/utils/builtins.h | 3 +++ 3 files changed, 6 insertions(+) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 6526bd4f43..aa3087c1a6 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -145,6 +145,8 @@ bool XLOG_DEBUG = false; int wal_segment_size = DEFAULT_XLOG_SEG_SIZE; +XLogRecPtr PgStartLSN = InvalidXLogRecPtr; + /* * Number of WAL insertion locks to use. A higher value allows more insertions * to happen concurrently, but adds some CPU overhead to flushing the WAL, diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c index ae31d66930..db296a641f 100644 --- a/src/backend/postmaster/postmaster.c +++ b/src/backend/postmaster/postmaster.c @@ -1444,6 +1444,7 @@ PostmasterMain(int argc, char *argv[]) * Remember postmaster startup time */ PgStartTime = GetCurrentTimestamp(); + PgStartLSN = GetXLogInsertRecPtr(); /* * Report postmaster status in the postmaster.pid file, to allow pg_ctl to diff --git a/src/include/utils/builtins.h b/src/include/utils/builtins.h index 2f8b46d6da..0cb24e10e6 100644 --- a/src/include/utils/builtins.h +++ b/src/include/utils/builtins.h @@ -17,6 +17,7 @@ #include "fmgr.h" #include "nodes/nodes.h" #include "utils/fmgrprotos.h" +#include "access/xlogdefs.h" /* Sign + the most decimal digits an 8-byte number could have */ #define MAXINT8LEN 20 @@ -82,6 +83,8 @@ extern void generate_operator_clause(fmStringInfo buf, Oid opoid, const char *rightop, Oid rightoptype); +extern PGDLLIMPORT XLogRecPtr PgStartLSN; + /* varchar.c */ extern int bpchartruelen(char *s, int len); -- 2.37.2