Information Functions

The following information related functions are available in Okera.

Function	Description
connected_user()	Returns the name of the connected user
current_database()	Returns the name of the currently selected database
effective_user()	Returns the name of the effective user
max_bigint()	Returns the maximum value for BIGINT values
max_int()	Returns the maximum value for INT values
max_smallint()	Returns the maximum value for SMALLINT values
max_tinyint()	Returns the maximum value for TINYINT values
min_bigint()	Returns the minimum value for BIGINT values
min_int()	Returns the minimum value for INT values
min_smallint()	Returns the minimum value for SMALLINT values
min_tinyint()	Returns the minimum value for TINYINT values
pid()	Returns the process ID of the server processing the request
user()	Same as effective_user() function
uuid()	Returns random UUIDs
version()	Returns the Okera version in use

The following explains some of the functions and statements in more detail.

• STRING connected_user, effective_user(), and user()

  Returns the information about the user connected to the Okera cluster. Typically the connected_user() function is returning the user or principal used internally between the cluster services. Usually user() and effective_user() are the same, since Okera is not supporting user impersonation.

  Example: Using the various user() functions

  > SELECT connected_user() AS conn_user,
      effective_user() AS eff_user,
      user() AS user;
  

  conn_user eff_user user --------- -------- ---- okera joebloggs joebloggs

  Note: When the cluster is kerberized, the connected user will contain the full Kerberos principal used internally, for instance okera/service@SAMPLECORP.TEST

• STRING current_database()

  Returns the name of the database set for the session.

  Example: Using the current_database() function

  > USE okera_sample;
  Ok
  > SELECT current_database();
  okera_sample
  

• STRING uuid()

  Returns random UUIDs.

  Example: Using the uuid() function

  > SELECT uuid(), uuid()
  aec3ac42-1327-410b-bea3-2e8d4fcc850e
  f25ed23b-a542-442b-8335-712acf6f3093
  

• STRING version()

  Returns the version of the server. Useful to verify that the cluster version matches what is expected.

  Example: Using the version() function

  > SELECT version()
  recordserviced version 1.5.1 RELEASE (build da0d7546090423b2bf80119fef21c4454b31978b)
  Built on Wed, 18 Sep 2019 01:55:44 PST