Quick question about indices (I’m getting my information from SingleStoreDB Cloud · SingleStore Documentation) — is 40 bytes of memory the average amount (I realize the precise value is probabilistic) both simple and composite indices take per row, or is that value per column indexed? I understand from the docs that if I index column A, I use 40 bytes per row no matter the datatype, and if I composite-index (A, B), I use 40 bytes per row per column, so 80 bytes per row. Is that correct?
VoltDB (3.3. Sizing for Capacity) is more explicit about index sizing, so that’s where I’m coming from. E.g. BINARY(1024) will have an index size of 1024+1 bytes, while BIGINT will have an index size of 8 bytes. Seems like it’s not so cut and dry for MemSQL.