Hello
My customer asked me about the relationship about PostgreSQL's following process:
wal writer process writer process
checkpoint process
Currently My understanding is:
If I execute some DML, then,Firstly , the related operation or data will be written to wal buffer.
Secondly, the related data will be written to data buffer(shared_buffer).
And because the above data structure, Then
wal writer process will periodically read from wal buffer, then write them into wal log.
writer process will read from data buffer and then write them into data file(eg: table).
And checkpointer process will read from data buffer then write them into wal log according to checkpoint_timeout and checkpoint_segments settings.
Is my understanding right?
Thanks!
Jian Gao