These changes also add a new type, PGColumnType, between PGColInfo and
PGScalarType, and they process PGRawColumnType values into PGColumnType
values during schema cache generation.
* allow altering type of a column iff session vars are defined in permissions
* use a sum type to define dependency reason
* set jwt expiry test's expiry time to 4 seconds
* derive Data instance for necessary types to simplify 'hasStaticExp'
1. Reuses postgres connections during startup which reduces the overhead of opening and closing connections.
2. Faster schema cache building. This is done by fetching all the required data in a single sql statement.
* remove phase one/two distinction and hdbquery typeclass
* move extensions to default-extensions
* switch to LazyTx which only acquires a connection if needed
* move defns from TH module into Ops module
* remove tojson orphan instance for http exception
* remove orphan instance for dmlp1
* getTopLevelNodes will not throw any exceptions
When using self referential relationships in boolean expressions, the exists clause incorrectly uses the table names to qualify columns which will be the same for parent table and the child table. This is now fixed by generating unique aliases as we traverse down the relationships.
* don't allow fkey based relations from/to a table that isn't tracked, fix#185
Check if remote table exist in metadata when creating foreign-key
based object relationship.
* add tests for adding object relation using fkey if remote table is untracked
