On Thu, Feb 28, 2019 at 3:34 PM Tom Lane <tgl@xxxxxxxxxxxxx> wrote:
Michael Lewis <mlewis@xxxxxxxxxxx> writes:
> Can you dumb down how to change the index or column type such that an index
> will be used for the && operator while intarray extension is installed? We
> have the intarray extension installed and I doubt that I can get it
> removed.
There's no magic nice solution to this, or we'd have told you about it.
Possible options:
1. Remove intarray extension.
2. Move intarray extension to a schema that's not in your search path.
3. Create an index using intarray's opclass, instead of or in addition
to the core-opclass index.
Thank you so much for you time in enumerating the options. What's the concern/problem/cost to re-creating the index with the intarray's opclass? If that's what will be used by && with the extension installed, then what's the downside?
I see significant code refactor for option 1 and 2 as it will have system wide impact rather than specific to the use of this particular column which is limited.
4. Rename intarray's && operator to something else (will bite you at
next dump/reload, where the renaming will be lost).
5. Always schema-qualify references to the core && operator.
Would a sixth option be to re-create the column as array type and keep the index as is and ensure that in queries, I am using conditions like ARRAY[1] && table.column_name rather than '{1}'::integer[] && table.column_name? Or would I still need to schema qualify references to the core && operator for it to be used?
If I created a table and disabled sequential scan and such, I suppose I could easily test that the index get used or not.
All of these have obvious downsides, especially if you're actively
using the intarray extension for other purposes.
regards, tom lane
