rockskip: Grab existing symbols from Postgres instead of ctags
Created by: chrismwendt
Fixes the error:
t=... lvl=eror msg=codeintel.symbols.parser.FetchRepositoryArchive error="readTar: exit status 128 (stderr: "fatal: pathspec 'REDACTED.proto' did not match any files")" count=1.000 elapsed=0.007 repo=... commitID=... paths=... paths=...
by deleting exactly the symbols associated with deleted files according to Postgres (source of truth) rather than ctags (impure).
Customers need to TRUNCATE rockskip_repos, rockskip_ancestry, rockskip_symbols; to kick off reindexing after upgrading.
The perf is about the same before and after to index sourcegraph/sourcegraph:
- Before 12m59s
- After: 12m45s
A deeper problem is that we're using an impure parser (ctags), which would be fixed by https://github.com/sourcegraph/sourcegraph/pull/36601
Depends on https://github.com/sourcegraph/sourcegraph/pull/36611
Test plan
Existing tests
