Hi! I need some help to understand why a transaction wiht a row delete aquire a AccessExclusiveLock and a row update a ExclusiveLock.
To ilustrate, a made this scenario: create table tblock ( id int primary key, value text ); insert into tblock values (1, 'somevalue'); First start Transaction 1: begin; update tblock set value = 'othervalue' where id = 1; -- keep this transaction opened After, start Transaction 2: begin; update tblock set value = 'onemorevalue' where id = 1; -- at this point, this transaction assumes a ExclusiveLock in the tuple; -- keep this transaction opend Then, start Transaction 3: begin; update tblock set value = 'lastofthevalues' where id = 1; -- here i can see this transaction trying to aquire a AccessExclusiveLock in this tuple So, my question is: why a delete row requires a AccessExclusiveLock in the tuple insteead of ExclusiveLock? Bellow, a image of a query over pg_locks: PostgreSQL version: 13 OS: Centos 7 Thanks in advance. -- Carlos Alves Especialista Sia Trecho 08, lotes 245 / 255 / 265 || +55 (61) 3039-9700 71205-080 || Guará || Brasília, DF 0800-6020097 www.tecnisys.com.br [1] Links: ------ [1] http://www.tecnisys.com.br
