Fix handling of defaultSchemaName on Postgresql

[nvoxland]

Description

When we first connect to postgresql, we call SET SEARCH_PATH=... to ensure the defaultSchemaName is first in the list.

However, when we roll back the connection (which we do throughout a liquibase run to ensure we have a clean connection) the search path on the connection gets rolled back to the initial value.

This PR restores the the reset of SEARCH_PATH in the rollback operation for postgreql

• Fixes sqlFile no longer has default schema set #2234
• Fixes Changesets containing plain sql-scripts are executed in postgres public schema but not in the configured liquibase default schema since 4.5.0 #2640

[nvoxland]

Notes and test results:

Things to be aware of

• I reproduced the problem by creating a changeset with a simple <sql>create table test (id int)</sql> change in it, then ran liquibase update with a defaultSchemaName=other and saw that the table was created in public rather than other
• This rollback call will be made for postgresql subclasses such as cockroachdb and enterprisedb
• It is the same init logic called at the beginning of every liquibase run, so I'm not worried about it
• I don't think the existing test automation can handle checking this, so there is no automated test

Things to worry about

• The re-added method was removed in Postgresql: Preserve existing search_path when setting the defaultSchemaName #1864. I think the removal was more of "we shouldn't need it" than a fix for the issue in 1864. But, we should re-check that what is reported in that is still fixed.

[github-actions]

Unit Test Results

  4 512 files  ±  0    4 512 suites  ±0   33m 26s ⏱️ - 4m 52s
  4 386 tests  - 92    4 172 ✔️  - 88     214 💤  - 4  0 ❌ ±0 
51 912 runs  ±  0  46 904 ✔️ +  4  5 008 💤  - 4  0 ❌ ±0 

Results for commit 363003e. ± Comparison against base commit ffd5cc1.

[ecarneiro01]

To test this I used the following changelog file: dbchangelog.zip which also includes this SQL file: sqlStatements.zip across the different databases that were tested.

In the changelog file there's a table creation using the tag. Meanwhile in the included SQL script there's a table creation, column creation, constraint creation and an information insert.

The results after running an update with this changelog for each database and using a defaultSchemaName: other are the following:

• Postgres
  • Verify successful creation of the database objects in the specified default schema
    • Table "Test" (through tag in the xml changelog). PASS
    • Tables "Person" and "Company" (through sqlStatements.sql script). PASS
    • Columns "Country" and "Worksfor_company_id" (through sqlStatements.sql script). PASS
    • Constraint "fk_person_worksfor" (through sqlStatements.sql script). PASS
    • Row insert in the table "Country" (through sqlStatements.sql script). PASS
• CockroachDB
  • Verify successful creation of the database objects in the specified default schema
    • Table "Test" (through tag in the xml changelog). PASS
    • Tables "Person" and "Company" (through sqlStatements.sql script). PASS
    • Columns "Country" and "Worksfor_company_id" (through sqlStatements.sql script). PASS
    • Constraint "fk_person_worksfor" (through sqlStatements.sql script). PASS
    • Row insert in the table "Country" (through sqlStatements.sql script). PASS
• EDB
  • Verify successful creation of the database objects in the specified default schema
    • Table "Test" (through tag in the xml changelog). PASS
    • Tables "Person" and "Company" (through sqlStatements.sql script). PASS
    • Columns "Country" and "Worksfor_company_id" (through sqlStatements.sql script). PASS
    • Constraint "fk_person_worksfor" (through sqlStatements.sql script). PASS
    • Row insert in the table "Country" (through sqlStatements.sql script). PASS

Also, to ensure that the PR #1864 fix was still working propertly, I also executed the test cases that were used to test those changes:

Verify successful update for tables, indexes and inert statements with spatial types and spatial methods:

• Box2D PASS
• GEOMETRY PASS
• GIST PASS
• ST_GeomFromText PASS

Verify a successful update for a procedure with spatial parameters (BOX2D, BOX3D, GEOMETRY and GEOMETRY_DUMP). PASS

Verify a successful rollback of a procedure with spatial parameters (BOX2D, BOX3D, GEOMETRY and GEOMETRY_DUMP). PASS

Verify a successful generate-changelog for tables, indexes and insert statements with spatial types and spatial methods. PASS

In the following file there's changelog directory with the generated updatesql and snapshot of the database after running the update command for each database (Postgres, Postgis, EDB and CockroachDB).
2812.zip

---

Environment information
Liquibase Version: [Core: //preserve-postgresql-searchpath/2459/363003/2022-04-29 21:12+0000, Pro: master/1076/a66427/2022-04-29T17:02:29Z] running under jdk-11.0.15.1
CockroachDB CCL v21.2.7 (x86_64-unknown-linux-gnu)
PostgreSQL 14.2 (Debian 14.2-1.pgdg110+1) on x86_64-pc-linux-gnu
PostGIS 3.1.4+dfsg-3.pgdg110+1 using Postgres 13.5-1.pgdg110+1
EDB repo ghcr.io/enterprisedb/postgresql:14-debian (which pulled Postgres 14.3-1.pgdg100+1)

[tooptoop4]

did this change da won dun break me version 4.11 ?

{"log":"  Position: 28 [Failed SQL: (0) SET SEARCH_PATH TO public, $user, public]\n","stream":"stderr","time":"2022-06-07T09:45:20.52837886Z"}
{"log":"\n","stream":"stderr","time":"2022-06-07T09:45:20.528382791Z"}```

[kataggart]

@tooptoop4 Would you mind opening a new issue reporting the details of your error so we can better track it and help resolve? Since this PR is already merged and released I don't want your issue to get lost. Thanks!