feat(postgres): limit collection to current database (#454)

* Handle database names containing spaces

* Remove functions and logic specific to Oracle and MySQL.

* Handle database names containing spaces

* Remove functions and logic specific to Oracle and MySQL.

* Limit database_details to just the current database.

* Limit database_details to just the current database.

* Add filter to Python collector.

Author: wpuziewicz

scripts/collector/postgres/sql/12/database_details.sql

@@ -22,6 +22,7 @@ with db as (
     pg_encoding_to_char(db.encoding) as character_set_encoding,
     pg_database_size(db.datname) as total_disk_size_bytes
   from pg_database db
+  where datname = current_database()
 ),
 db_size as (
   select s.datid as database_oid,

scripts/collector/postgres/sql/13/database_details.sql

@@ -22,6 +22,7 @@ with db as (
     pg_encoding_to_char(db.encoding) as character_set_encoding,
     pg_database_size(db.datname) as total_disk_size_bytes
   from pg_database db
+  where datname = current_database()
 ),
 db_size as (
   select s.datid as database_oid,

scripts/collector/postgres/sql/base/database_details.sql

@@ -22,6 +22,7 @@ with db as (
     pg_encoding_to_char(db.encoding) as character_set_encoding,
     pg_database_size(db.datname) as total_disk_size_bytes
   from pg_database db
+  where datname = current_database() 
 ),
 db_size as (
   select s.datid as database_oid,

src/dma/collector/sql/sources/postgres/collection-database_details.sql

@@ -23,6 +23,7 @@ with db as (
     pg_encoding_to_char(db.encoding) as character_set_encoding,
     pg_database_size(db.datname) as total_disk_size_bytes
   from pg_database db
+  where datname = current_database()
 ),
 db_size as (
   select s.datid as database_oid,
@@ -146,6 +147,7 @@ with db as (
     pg_encoding_to_char(db.encoding) as character_set_encoding,
     pg_database_size(db.datname) as total_disk_size_bytes
   from pg_database db
+  where datname = current_database()
 ),
 db_size as (
   select s.datid as database_oid,
@@ -269,6 +271,7 @@ with db as (
     pg_encoding_to_char(db.encoding) as character_set_encoding,
     pg_database_size(db.datname) as total_disk_size_bytes
   from pg_database db
+  where datname = current_database()
 ),
 db_size as (
   select s.datid as database_oid,