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.
* build schema cache function without db setup
The setup shouldn't happen for sync. The database is already setup by the instance which generated the event. This means that the sync is now faster.
* use SQL loop to drop hdb_views schema views and routines with ordering
This avoids deadlocks when schema is being changed concurrently
* schema sync now only processes the latest event
This becomes useful when a lot of schema change
events happen while we are still processing an
earlier event.
* split stm transactions when snapshotting to make it faster
* mx subs: push to both old and new sinks at the same time
* expose dev APIs through allowed APIs flag
* fix timestamp column shown as text in modify section
* fix foreign key update bug in case of capital letters in name
* show column type, default value, constraint names as properties in modify section
* display disabled action btns in browse rows if no primary key set
* add tooltips to event trigger / remote schema try it out examples
* add types to represent unparsed http gql requests
This will help when we add caching of frequently used ASTs
* query plan caching
* move livequery to execute
* add multiplexed module
* session variable can be customised depending on the context
Previously the value was always "current_setting('hasura.user')"
* get rid of typemap requirement in reusable plan
* subscriptions are multiplexed when possible
* use lazytx for introspection to avoid acquiring a pg connection
* refactor to make execute a completely decoupled module
* don't issue a transaction for a query
* don't use current setting for explained sql
* move postgres related types to a different module
* validate variableValues on postgres before multiplexing subs
* don't user current_setting for queries over ws
* plan_cache is only visible when developer flag is enabled
* introduce 'batch size' when multiplexing subscriptions
* bump stackage to 13.16
* fix schema_stitching test case error code
* store hashes instead of actual responses for subscriptions
* internal api to dump subscriptions state
* remove PlanCache from SchemaCacheRef
* allow live query options to be configured on server startup
* capture metrics for multiplexed subscriptions
* more metrics captured for multiplexed subs
* switch to tvar based hashmap for faster snapshotting
* livequery modules do not expose internal details
* fix typo in live query env vars
* switch to hasura's pg-client-hs
