Allow users to specify the destination schema name

[Iain-S]

We manually set the schema name in for the whole connection session using an explicit SET SEARCH_PATH TO statement.

This allows the user to have a different destination schema name than the source schema.

The disadvantage is that we cannot support multiple source schemas (not that we did previously, but this makes it harder), though postgres does allow you to set more than one schema on a search path with SET SEARCH_PATH TO schema1, schema2;.

Would appreciate some testing on a real database.

[Iain-S]

I'm not sure what will happen if the src schema is myschema and the dst schema is left empty. I think it will try to make the tables in the public schema. Is that undesirable? Should the default behaviour be to set the dst schema the same as the src one?

[mhauru]

Looks good, I only have a few style questions/points. Also, happy with how make_tables now avoids calling run (at the cost of some importlib stuff, but no free lunch).

[mhauru]

I'm not sure what will happen if the src schema is myschema and the dst schema is left empty. I think it will try to make the tables in the public schema. Is that undesirable? Should the default behaviour be to set the dst schema the same as the src one?

I wouldn't mind it if it used public. Given that it's the postgres default, I don't think it's unreasonable to have it be our default too.

[mhauru]

I tried running with and without dst_schema set, ran into a couple of tiny issues. I pushed a commit fixing them, with those my manual little test case works.