Track · 2:30 · Liner note
A Reunion of Parts
In a ClickHouse MergeTree table every insert writes an immutable part, and background merges combine smaller parts into larger ones to keep reads efficient.
Every insert into a ClickHouse MergeTree table leaves behind a new immutable part. Left alone, parts would pile up and reads would slow, so background merges combine them into fewer, larger ones. A Reunion of Parts is that gathering, done quietly while you work.
You help by inserting in batches instead of row by row. Thousands of tiny inserts create parts faster than merges can absorb them, and eventually the server pushes back with a too-many-parts error. Fewer, larger writes keep the reunion calm.