Tom Lane a écrit : > Guillaume Lelarge <[EMAIL PROTECTED]> writes: >> I try to answer a simple question : what happens when I do a simple >> "INSERT" on a just started PostgreSQL server. > >> From what I understand with the INSERT statement, here is what happens : >> * backend loads first (and only) block from footable file into a shared >> buffer >> * it modifies this block on the shared buffer, and sets it as dirty > > Right, and it also makes a WAL log entry about this action. >
The WAL log entry is made on the wal buffers (in memory). As soon as this statement is commited (in my example, it's right now, but in a BEGIN ... COMMIT statement, at COMMIT time), the wal buffer is flushed on WAL files. It can be flushed before if wal buffer is not big enough to contain all the current transactions. Am I right ? Thanks for your answer, I think I better understand the complete process. Regards. -- Guillaume. http://www.postgresqlfr.org http://dalibo.com ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
