Class: Rake::DataTask::Greenplum

Inherits:
Postgres show all
Defined in:
lib/data_task/adapters/greenplum.rb

Constant Summary collapse

TABLE_TRACKER_HELPER_NAME = 
"operations"

Constants inherited from Db

Db::LOG, Db::TABLE_TRACKER_COLUMNS, Db::TABLE_TRACKER_NAME

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Postgres

#[], #create_table, #create_view, #drop_view, #execute, #initialize, #operations_supported, #reset_tracking, #set_up_tracking, #table_exists?, #table_mtime, #table_tracker_columns, #tear_down_tracking, #truncate_table, #view_exists?, #with_role, #with_search_path

Methods included from ConnectionPersistence

#persist_connection, #persisted_connection

Methods inherited from Db

#operation_values, #relation_type_values, #table_tracker_columns

Constructor Details

This class inherits a constructor from Rake::DataTask::Postgres

Class Method Details

.set_up_tracking(options) ⇒ Object 



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# File 'lib/data_task/adapters/greenplum.rb', line 12

def self.set_up_tracking options
  tear_down_tracking options
  super

  execute "alter table #{TABLE_TRACKER_NAME} rename to #{TABLE_TRACKER_HELPER_NAME}"

  # Greenplum tracks CREATE and TRUNCATE operations in its pg_stat_operations system view.
  # Join this view with the tracking table so that we can track CREATE and TRUNCATE from within
  # the database instead of from application code.

  execute "    create view fixed_pg_stat_operations as\n    -- GP's pg_stat_operations enum values like 'TABLE' are inconsistent so fix them here\n    select\n      pso.classname, \n      pso.objname,\n      pso.objid,\n      pso.schemaname,\n      pso.usestatus,\n      pso.usename,\n      pso.actionname,\n      case \n        when pso.actionname = 'TRUNCATE' then '\#{relation_type_values[:table]}'\n        when pso.subtype = 'TABLE' then '\#{relation_type_values[:table]}'\n        else pso.subtype\n      end as subtype,\n      pso.statime\n    from pg_stat_operations pso\n  EOSQL\n\n  execute <<-EOSQL\n    create view \#{TABLE_TRACKER_NAME} as \n    select\n      relation_name,\n      relation_type,\n      operation,\n      time\n    from (\n\n      select\n        a.*,\n        rank() over (partition by relation_name, relation_type order by time desc)\n      from (\n\n        -- select all CREATE and TRUNCATE operations tracked by Greenplum\n        select\n          pso.objname as relation_name,\n          pso.subtype as relation_type,\n          pso.actionname as operation,\n          pso.statime as time\n        from fixed_pg_stat_operations pso\n        where pso.actionname not in ('ANALYZE', 'VACUUM')\n\n        union all\n\n        -- select all operations tracked by Greenplum (PostgreSQL) table rules \n        select\n          ttb.relation_name,\n          ttb.relation_type,\n          ttb.operation,\n          ttb.time\n        from \n          \#{TABLE_TRACKER_HELPER_NAME} ttb\n          -- return only operations for tables that exist in system tables\n          join fixed_pg_stat_operations pso on (\n            ttb.relation_name = pso.objname and\n            ttb.relation_type = pso.subtype and\n            pso.actionname = 'CREATE'\n          )\n\n        ) a\n      ) b \n    -- take only the latest operation per table\n    where rank = 1\n  EOSQL\n\n  # make sure we do deletes and inserts on the helper table, not the view\n  execute <<-EOSQL\n    create rule delete_operation_record as on delete to \#{TABLE_TRACKER_NAME} \n      do instead\n      delete from \#{TABLE_TRACKER_HELPER_NAME} \n      where\n        relation_name = OLD.relation_name and\n        relation_type = OLD.relation_type and\n        operation = OLD.operation\n    ;\n\n    create rule insert_operation_record as on insert to \#{TABLE_TRACKER_NAME} \n      do instead\n      insert into \#{TABLE_TRACKER_HELPER_NAME} values (\n        NEW.relation_name,\n        NEW.relation_type,\n        NEW.operation,\n        NEW.time\n      )\n    ;\n  EOSQL\nend\n"

.tear_down_tracking(options) ⇒ Object 



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# File 'lib/data_task/adapters/greenplum.rb', line 111

def self.tear_down_tracking options
  drop_view "fixed_pg_stat_operations"
  drop_view TABLE_TRACKER_NAME
  drop_table TABLE_TRACKER_HELPER_NAME
end

Instance Method Details

#drop_table(table_name) ⇒ Object 



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# File 'lib/data_task/adapters/greenplum.rb', line 121

def drop_table table_name
  execute "drop table if exists #{table_name} cascade"
  return if table_name.casecmp(TABLE_TRACKER_HELPER_NAME) == 0 || 
    table_name.casecmp(TABLE_TRACKER_NAME) == 0
  track_drop table_name
end

#track_drop(table_name) ⇒ Object 



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# File 'lib/data_task/adapters/greenplum.rb', line 128

def track_drop table_name
  execute "    delete from \#{TABLE_TRACKER_HELPER_NAME} \n    where \n      relation_name = '\#{table_name}' and \n      relation_type = '\#{relation_type_values[:table]}'\n  EOSQL\nend\n"

#tracking_tables? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/data_task/adapters/greenplum.rb', line 117

def tracking_tables?
  view_exists?(TABLE_TRACKER_NAME)
end