Re: efficiency random values / sequential ID values in indexes

On Mon, Apr 15, 2024 at 6:05 AM Sanjay Minni <sanjay(dot)minni(at)gmail(dot)com> wrote:

> Hi
>
> Is there any appreciable difference in using random values or sequential
> values in indexes
>
> in a multi tenanted application there is a choice that the single field
> ID's value is totally random / UUID or the numbers are created with a
> prefix of the tenant. Since all access will be within a tenant only, will
> it make any performance difference between using purely random values vs
> <tenant no prefix part>+<random value>.
>

Two benefits of <tenant no prefix part>+<random value>:

1. In a non-partitioned table, it gives your index "locality of data": all
of customer X's record pointers are in *This* subtree. Makes buffers more
efficient when a customer runs reports. Bonus points if you then regularly
CLUSTER using that table.
2. Makes table partitioning by <tenant prefix> much easier. That also
enhances locality of data.

Just make sure that the field ID is BIGINT...