adapted for PostgreSQL 16

[pierreforstmann]

Hello,

I have tried to adapt your code for PostgreSQL 16 (because in version 17 there is pg_buffercache_evict in pg_buffercache):

Currently I have following test case;

create extension pg_prewarm;
create extension pg_buffercache;
create extension pg_flushcache;

create table t ( a int, b text );
insert into t select i, i::text from generate_series(1,10000) i;
select pg_prewarm ( 't', 'buffer', 'main', null, null );

select pg_relation_filepath('t');
 pg_relation_filepath 
----------------------
 base/16385/16410
(1 row)

pierre=# select count(*) from pg_buffercache where relfilenode = 16410;
 count 
-------
    58
(1 row)

pierre=# select pg_drop_rel_cache(16410);
 pg_drop_rel_cache 
-------------------
 
(1 row)

pierre=# select count(*) from pg_buffercache where relfilenode = 16410;
 count 
-------
     4
(1 row)