From c8a1bc01c6b05d394d5b6d0e0f594ccf9b46bbcb Mon Sep 17 00:00:00 2001 From: Peter Eisentraut Date: Mon, 12 Sep 2022 09:38:07 +0200 Subject: [PATCH] Use float8 datatype for percentiles in pg_walinspect stat functions pg_walinspect uses datatype double (double precision floating point number) for WAL stats percentile calculations and expose them via float4 (single precision floating point number), which an unnecessary loss of precision and confusing. Even though, it's harmless that way, let's use float8 (double precision floating-point number) to be in sync with what pg_walinspect does internally and what it exposes to the users. This seems to be the pattern used elsewhere in the code. Reported-by: Peter Eisentraut Author: Bharath Rupireddy Reviewed-by: Peter Eisentraut Discussion: https://www.postgresql.org/message-id/36ee692b-232f-0484-ce94-dc39d82021ad%40enterprisedb.com --- contrib/pg_walinspect/pg_walinspect--1.0.sql | 16 ++++++++-------- contrib/pg_walinspect/pg_walinspect.c | 8 ++++---- doc/src/sgml/pgwalinspect.sgml | 16 ++++++++-------- 3 files changed, 20 insertions(+), 20 deletions(-) diff --git a/contrib/pg_walinspect/pg_walinspect--1.0.sql b/contrib/pg_walinspect/pg_walinspect--1.0.sql index 4243516d8a..08b3dd5556 100644 --- a/contrib/pg_walinspect/pg_walinspect--1.0.sql +++ b/contrib/pg_walinspect/pg_walinspect--1.0.sql @@ -80,13 +80,13 @@ CREATE FUNCTION pg_get_wal_stats(IN start_lsn pg_lsn, IN per_record boolean DEFAULT false, OUT "resource_manager/record_type" text, OUT count int8, - OUT count_percentage float4, + OUT count_percentage float8, OUT record_size int8, - OUT record_size_percentage float4, + OUT record_size_percentage float8, OUT fpi_size int8, - OUT fpi_size_percentage float4, + OUT fpi_size_percentage float8, OUT combined_size int8, - OUT combined_size_percentage float4 + OUT combined_size_percentage float8 ) RETURNS SETOF record AS 'MODULE_PATHNAME', 'pg_get_wal_stats' @@ -102,13 +102,13 @@ CREATE FUNCTION pg_get_wal_stats_till_end_of_wal(IN start_lsn pg_lsn, IN per_record boolean DEFAULT false, OUT "resource_manager/record_type" text, OUT count int8, - OUT count_percentage float4, + OUT count_percentage float8, OUT record_size int8, - OUT record_size_percentage float4, + OUT record_size_percentage float8, OUT fpi_size int8, - OUT fpi_size_percentage float4, + OUT fpi_size_percentage float8, OUT combined_size int8, - OUT combined_size_percentage float4 + OUT combined_size_percentage float8 ) RETURNS SETOF record AS 'MODULE_PATHNAME', 'pg_get_wal_stats_till_end_of_wal' diff --git a/contrib/pg_walinspect/pg_walinspect.c b/contrib/pg_walinspect/pg_walinspect.c index bed01126b5..6845198430 100644 --- a/contrib/pg_walinspect/pg_walinspect.c +++ b/contrib/pg_walinspect/pg_walinspect.c @@ -436,13 +436,13 @@ FillXLogStatsRow(const char *name, values[i++] = CStringGetTextDatum(name); values[i++] = Int64GetDatum(n); - values[i++] = Float4GetDatum(n_pct); + values[i++] = Float8GetDatum(n_pct); values[i++] = Int64GetDatum(rec_len); - values[i++] = Float4GetDatum(rec_len_pct); + values[i++] = Float8GetDatum(rec_len_pct); values[i++] = Int64GetDatum(fpi_len); - values[i++] = Float4GetDatum(fpi_len_pct); + values[i++] = Float8GetDatum(fpi_len_pct); values[i++] = Int64GetDatum(tot_len); - values[i++] = Float4GetDatum(tot_len_pct); + values[i++] = Float8GetDatum(tot_len_pct); Assert(i == ncols); } diff --git a/doc/src/sgml/pgwalinspect.sgml b/doc/src/sgml/pgwalinspect.sgml index de63a70965..1a1bee7d6a 100644 --- a/doc/src/sgml/pgwalinspect.sgml +++ b/doc/src/sgml/pgwalinspect.sgml @@ -164,13 +164,13 @@ postgres=# select start_lsn, end_lsn, prev_lsn, xid, resource_manager, record_ty per_record boolean DEFAULT false, "resource_manager/record_type" OUT text, count OUT int8, - count_percentage OUT float4, + count_percentage OUT float8, record_length OUT int8, - record_length_percentage OUT float4, + record_length_percentage OUT float8, fpi_length OUT int8, - fpi_length_percentage OUT float4, + fpi_length_percentage OUT float8, combined_size OUT int8, - combined_size_percentage OUT float4) + combined_size_percentage OUT float8) returns setof record @@ -241,13 +241,13 @@ postgres=# select * from pg_get_wal_stats('0/14AFC30', '0/15011D7', true) where per_record boolean DEFAULT false, "resource_manager/record_type" OUT text, count OUT int8, - count_percentage OUT float4, + count_percentage OUT float8, record_length OUT int8, - record_length_percentage OUT float4, + record_length_percentage OUT float8, fpi_length OUT int8, - fpi_length_percentage OUT float4, + fpi_length_percentage OUT float8, combined_size OUT int8, - combined_size_percentage OUT float4) + combined_size_percentage OUT float8) returns setof record