Database field have key information fields. A, B, C
Data volume is expected to more than million, must, B, C have repeatedly written to update requirement,
If I can have the following query scenario A=XX and reverse or ascending order according to B or A XX and ascending order according to the C=
Is set to A single index directly is enough, or set A, B and A, two joint index C?

CodePudding user response:

The two combined index
A + B
A + C