3 ms·
Probably more appropriate to think of ES as relying on a WAL for managing an ordered event stream. When getting the current state of a business object e.g. "SEL
by tomnipotent 9y ago
Probably more appropriate to think of ES as relying on a WAL for managing an ordered event stream. When getting the current state of a business object e.g. "SELECT * FROM table WHERE pk=313", you would replay the event log to get current state and discard it when you're done. Mutation is only done by adding an event to the stream.
It's not uncommon to see RDBMS's still used to improve read performance (but not as a source of truth, just a cache with SQL).
- fnord123 9y agoRight, and then, if the domain allows it, you can compact the logs into the current state so the compacted state is the single source of truth. e.g. HDFS works this way by having an fsimage and the edit logs. After a compaction, the fsimage is the HDFS namespace. The RDBMS that you mention is just a coarse tool for doing the same thing (IIUC).