Creating an index

TimescaleDB and PostgreSQL
,
1

The Timescale documentation says “You can create an index on any combination of columns, as long as you include the time column, for time-series data.” [1] and " You can create an index on any combination of columns, as long as you include the time column, for time-series data." [2].

Why so? Why can’t I create an index of any (non time) related column? Reading [3], it seems that including the “time” column is only required if you want to create a unique index, but not a regular index. Is this so?

[1]

[2]

[3]
htt ps://github.com/timescale/timescaledb/issues/488#issuecomment-376938255

2

Hi, you can just create index but uniqueness would be expensive because it would need to navigate into all the chunks to confirm it. For performance reasons we haven’t implemented it. It would just slow down the ingest speed because of such validation. Index not unique just works because you don’t have constraints and adding the time column allow it to divide the index creating one index per chunk.