Postgresql Datastores

This page describes how a postgresql datastore attached to a daemon (i.e. referenced in the daemon's configuration file) is managed in Sakura.

The code of the postgresql db driver and the hub code saving metadata in the central db follow these principles.

User and rights management

For security reasons, users and rights are configured right into the postgresql service. A sakura user with login <user> is mapped to a postgresql user sakura_<user>.

User rights are implemented as follows:

User right	Implementation
datastore read access (i.e. connect there)	sakura_<user> exists
datastore write access (i.e. create databases there)	sakura_<user> has CREATEDB grant
database read access	sakura_<user> has CONNECT privilege on this database
database write access	sakura_<user> has CREATE grant on this database
database ownership	sakura_<user> is OWNER of this database

Metadata management

Metadata not involved in data processing is stored in the Hub's central database.

Database-related Metadata

metadata type	Implementation	Default value
database name	centraldb.Database.name field	postgresql db name
database short description	centraldb.Database.short_desc field	none
database creation date	centraldb.Database.created field	none
database tags	centraldb.DatabaseTags table	none
database contacts	centraldb.DatabaseContacts table	The database owner

Table-related Metadata

metadata type	Implementation	Default value
table name	centraldb.DBTable.name field	postgresql table name
table short description	centraldb.DBTable.short_desc field	none
table creation date	centraldb.DBTable.created field	none

Column-related Metadata

metadata type	Implementation	Default value
column tags	centraldb.DBColumnTags table	none