This topic describes the internal architecture of PolarDB for PostgreSQL(Compatible with Oracle).

Internal architecture
Architecture componentDescription
shared_buffer_poolThe shared buffer, which is used to buffer data for fast data processing.
wal bufferThe log buffer. Write-ahead logging (WAL) logs must be written to the log buffer first, and then flushed to disks after the log size reaches the threshold or the commit operation is triggered.
clog bufferThe buffer for storing the commit log (clog). The clog is used to record the transaction commit status. You can determine the transaction visibility based on the clog.
local storageThe local storage.