/*
 * SQL Information Schema
 * as defined in ISO 9075-2:1999 chapter 20
 *
 * Copyright 2002, PostgreSQL Global Development Group
 *
 * $Id: information_schema.sql,v 1.4 2003/03/20 05:06:55 momjian Exp $
 */


/*
 * 20.2
 * INFORMATION_SCHEMA schema
 */

CREATE SCHEMA information_schema;
GRANT USAGE ON SCHEMA information_schema TO PUBLIC;
SET search_path TO information_schema, public;


-- Note: 20.3 follows later.  Some genius screwed up the order in the standard.


/*
 * 20.4
 * CARDINAL_NUMBER domain
 */

CREATE DOMAIN cardinal_number AS integer
    CONSTRAINT cardinal_number_domain_check CHECK (value >= 0);


/*
 * 20.5
 * CHARACTER_DATA domain
 */

CREATE DOMAIN character_data AS character varying;


/*
 * 20.6
 * SQL_IDENTIFIER domain
 */

CREATE DOMAIN sql_identifier AS character varying;


/*
 * 20.3
 * INFORMATION_SCHEMA_CATALOG_NAME view
 */

CREATE VIEW information_schema_catalog_name AS
    SELECT CAST(current_database() AS sql_identifier) AS catalog_name;

GRANT SELECT ON information_schema_catalog_name TO PUBLIC;


/*
 * 20.7
 * TIME_STAMP domain
 */

CREATE DOMAIN time_stamp AS timestamp(2)
    DEFAULT current_timestamp(2);


/*
 * 20.13
 * CHECK_CONSTRAINTS view
 */

CREATE VIEW check_constraints AS
    SELECT CAST(current_database() AS sql_identifier) AS constraint_catalog,
           CAST(rs.nspname AS sql_identifier) AS constraint_schema,
           CAST(con.conname AS sql_identifier) AS constraint_name,
           CAST(con.consrc AS character_data) AS check_clause
    FROM pg_namespace rs, pg_constraint con
         left outer join pg_class c on (c.oid = con.conrelid)
         left outer join pg_type t on (t.oid = con.contypid),
         pg_user u
    WHERE rs.oid = con.connamespace
          AND u.usesysid IN (c.relowner, t.typowner)
          AND u.usename = current_user
          AND con.contype = 'c';

GRANT SELECT ON check_constraints TO PUBLIC;


/*
 * 20.15
 * COLUMN_DOMAIN_USAGE view
 */

CREATE VIEW column_domain_usage AS
    SELECT CAST(current_database() AS sql_identifier) AS domain_catalog,
           CAST(nt.nspname AS sql_identifier) AS domain_schema,
           CAST(t.typname AS sql_identifier) AS domain_name,
           CAST(current_database() AS sql_identifier) AS table_catalog,
           CAST(nc.nspname AS sql_identifier) AS table_schema,
           CAST(c.relname AS sql_identifier) AS table_name,
           CAST(a.attname AS sql_identifier) AS column_name

    FROM pg_type t, pg_namespace nt, pg_class c, pg_namespace nc,
         pg_attribute a, pg_user u

    WHERE t.typnamespace = nt.oid AND t.typtype = 'd'
          AND c.relnamespace = nc.oid AND a.attrelid = c.oid
          AND a.atttypid = t.oid AND t.typowner = u.usesysid
          AND u.usename = current_user;

GRANT SELECT ON column_domain_usage TO PUBLIC;


/*
 * 20.16
 * COLUMN_PRIVILEGES
 */

-- PostgreSQL does not have column privileges, so this view is empty.
-- (Table privileges do not also count as column privileges.)

CREATE VIEW column_privileges AS
    SELECT CAST(null AS sql_identifier) AS grantor,
           CAST(null AS sql_identifier) AS grantee,
           CAST(null AS sql_identifier) AS table_catalog,
           CAST(null AS sql_identifier) AS table_schema,
           CAST(null AS sql_identifier) AS table_name,
           CAST(null AS sql_identifier) AS column_name,
           CAST(null AS character_data) AS privilege_type,
           CAST(null AS character_data) AS is_grantable
    WHERE false;

GRANT SELECT ON column_privileges TO PUBLIC;


/*
 * 20.18
 * COLUMNS view
 */

CREATE VIEW columns AS
    SELECT CAST(current_database() AS sql_identifier) AS table_catalog,
           CAST(nc.nspname AS sql_identifier) AS table_schema,
           CAST(c.relname AS sql_identifier) AS table_name,
           CAST(a.attname AS sql_identifier) AS column_name,
           CAST(a.attnum AS cardinal_number) AS ordinal_position,
           CAST(
             CASE WHEN u.usename = current_user THEN a.adsrc ELSE null END
             AS character_data)
             AS column_default,
           CAST(CASE WHEN a.attnotnull THEN 'NO' ELSE 'YES' END
             AS character_data)
             AS is_nullable,
           CAST(format_type(a.atttypid, null) AS character_data)
             AS data_type,

           CAST(
             CASE WHEN a.atttypid IN (25, 1042, 1043, 1560, 1562) AND a.atttypmod <> -1
                  THEN a.atttypmod - 4
                  ELSE null END
             AS cardinal_number)
             AS character_maximum_length,

           CAST(
             CASE WHEN a.atttypid IN (25, 1042, 1043) THEN 2^30 ELSE null END
             AS cardinal_number)
             AS character_octet_length,

           CAST(
             CASE WHEN a.atttypid IN (1700) THEN ((a.atttypmod - 4) >> 16) & 65535 ELSE null END
             AS cardinal_number)
             AS numeric_precision,

           CAST(
             CASE WHEN a.atttypid IN (1700) THEN 10 ELSE null END
             AS cardinal_number)
             AS numeric_precision_radix,

           CAST(
             CASE WHEN a.atttypid IN (1700) THEN (a.atttypmod - 4) & 65535 ELSE null END
             AS cardinal_number)
             AS numeric_scale,

           CAST(
             CASE WHEN a.atttypid IN (1083, 1114, 1184, 1266)
                  THEN (CASE WHEN a.atttypmod <> -1 THEN a.atttypmod ELSE null END)
                  WHEN a.atttypid IN (1186)
                  THEN (CASE WHEN a.atttypmod <> -1 THEN a.atttypmod & 65535 ELSE null END)
                  ELSE null END
             AS cardinal_number)
             AS datetime_precision,

           CAST(null AS character_data) AS interval_type, -- XXX
           CAST(null AS character_data) AS interval_precision, -- XXX

           CAST(null AS sql_identifier) AS character_set_catalog,
           CAST(null AS sql_identifier) AS character_set_schema,
           CAST(null AS sql_identifier) AS character_set_name,

           CAST(null AS sql_identifier) AS collation_catalog,
           CAST(null AS sql_identifier) AS collation_schema,
           CAST(null AS sql_identifier) AS collation_name,

           CAST(CASE WHEN t.typbasetype <> 0 THEN current_database() ELSE null END
             AS sql_identifier) AS domain_catalog,
           CAST(CASE WHEN t.typbasetype <> 0 THEN nt.nspname ELSE null END
             AS sql_identifier) AS domain_schema,
           CAST(CASE WHEN t.typbasetype <> 0 THEN t.typname ELSE null END
             AS sql_identifier) AS domain_name,

           CAST(CASE WHEN t.typbasetype = 0 THEN current_database() ELSE null END
             AS sql_identifier) AS udt_catalog,
           CAST(CASE WHEN t.typbasetype = 0 THEN nt.nspname ELSE null END
             AS sql_identifier) AS udt_schema,
           CAST(CASE WHEN t.typbasetype = 0 THEN t.typname ELSE null END
             AS sql_identifier) AS udt_name,

           CAST(null AS sql_identifier) AS scope_catalog,
           CAST(null AS sql_identifier) AS scope_schema,
           CAST(null AS sql_identifier) AS scope_name,

           CAST(null AS cardinal_number) AS maximum_cardinality,
           CAST(null AS sql_identifier) AS dtd_identifier,
           CAST('NO' AS character_data) AS is_self_referencing

           FROM (pg_attribute LEFT JOIN pg_attrdef ON attrelid = adrelid AND attnum = adnum) AS a,
                pg_class c, pg_namespace nc, pg_type t, pg_namespace nt, pg_user u

           WHERE a.attrelid = c.oid
                 AND a.atttypid = t.oid
                 AND u.usesysid = c.relowner
                 AND nc.oid = c.relnamespace
                 AND nt.oid = t.typnamespace
                 AND u.usename = current_user

                 AND a.attnum > 0 AND NOT a.attisdropped AND c.relkind in ('r', 'v');

GRANT SELECT ON columns TO PUBLIC;


/*
 * 20.24
 * DOMAIN_CONSTRAINTS view
 */

CREATE VIEW domain_constraints AS
    SELECT CAST(current_database() AS sql_identifier) AS constraint_catalog,
           CAST(rs.nspname AS sql_identifier) AS constraint_schema,
           CAST(con.conname AS sql_identifier) AS constraint_name,
           CAST(current_database() AS sql_identifier) AS domain_catalog,
           CAST(n.nspname AS sql_identifier) AS domain_schema,
           CAST(t.typname AS sql_identifier) AS domain_name,
           CAST(CASE WHEN condeferrable THEN 'YES' ELSE 'NO' END
             AS character_data) AS is_deferrable,
           CAST(CASE WHEN condeferred THEN 'YES' ELSE 'NO' END
             AS character_data) AS initially_deferred
    FROM pg_namespace rs, pg_namespace n, pg_constraint con, pg_type t, pg_user u
    WHERE rs.oid = con.connamespace
          AND n.oid = t.typnamespace
          AND u.usesysid = t.typowner
          AND u.usename = current_user
          AND t.oid = con.contypid;

GRANT SELECT ON domain_constraints TO PUBLIC;


/*
 * 20.26
 * DOMAINS view
 */

CREATE VIEW domains AS
    SELECT CAST(current_database() AS sql_identifier) AS domain_catalog,
           CAST(rs.nspname AS sql_identifier) AS domain_schema,
           CAST(t.typname AS sql_identifier) AS domain_name,
           CAST(format_type(t.typbasetype, null) AS character_data)
             AS data_type,

           CAST(
             CASE WHEN t.typbasetype IN (25, 1042, 1043, 1560, 1562) AND t.typtypmod <> -1
                  THEN t.typtypmod - 4
                  ELSE null END
             AS cardinal_number)
             AS character_maximum_length,

           CAST(
             CASE WHEN t.typbasetype IN (25, 1042, 1043) THEN 2^30 ELSE null END
             AS cardinal_number)
             AS character_octet_length,
           CAST(null AS sql_identifier) AS character_set_catalog,
           CAST(null AS sql_identifier) AS character_set_schema,
           CAST(null AS sql_identifier) AS character_set_name,

           CAST(null AS sql_identifier) AS collation_catalog,
           CAST(null AS sql_identifier) AS collation_schema,
           CAST(null AS sql_identifier) AS collation_name,

           CAST(
             CASE WHEN t.typbasetype IN (1700) THEN ((t.typtypmod - 4) >> 16) & 65535 ELSE null END
             AS cardinal_number)
             AS numeric_precision,

           CAST(
             CASE WHEN t.typbasetype IN (1700) THEN 10 ELSE null END
             AS cardinal_number)
             AS numeric_precision_radix,

           CAST(
             CASE WHEN t.typbasetype IN (1700) THEN (t.typtypmod - 4) & 65535 ELSE null END
             AS cardinal_number)
             AS numeric_scale,

           CAST(
             CASE WHEN t.typbasetype IN (1083, 1114, 1184, 1266)
                  THEN (CASE WHEN t.typtypmod <> -1 THEN t.typtypmod ELSE null END)
                  WHEN t.typbasetype IN (1186)
                  THEN (CASE WHEN t.typtypmod <> -1 THEN t.typtypmod & 65535 ELSE null END)
                  ELSE null END
             AS cardinal_number)
             AS datetime_precision,

           CAST(null AS character_data) AS interval_type, -- XXX
           CAST(null AS character_data) AS interval_precision, -- XXX

           CAST(typdefault AS character_data) AS domain_default,

           CAST(CASE WHEN t.typbasetype = 0 THEN current_database() ELSE null END
             AS sql_identifier) AS udt_catalog,
           CAST(CASE WHEN t.typbasetype = 0 THEN rs.nspname ELSE null END
             AS sql_identifier) AS udt_schema,
           CAST(CASE WHEN t.typbasetype = 0 THEN t.typname ELSE null END
             AS sql_identifier) AS udt_name,

           CAST(null AS sql_identifier) AS scope_catalog,
           CAST(null AS sql_identifier) AS scope_schema,
           CAST(null AS sql_identifier) AS scope_name,

           CAST(null AS cardinal_number) AS maximum_cardinality,
           CAST(null AS sql_identifier) AS dtd_identifier

    FROM pg_namespace rs,
         pg_type t,
         pg_user u

    WHERE rs.oid = t.typnamespace
          AND t.typtype = 'd'
          AND t.typowner = u.usesysid
          AND (u.usename = CURRENT_USER
              OR EXISTS (SELECT 1
                         FROM pg_user AS u2
                         WHERE rs.nspowner = u2.usesysid
                           AND u2.usename = CURRENT_USER)
              OR EXISTS (SELECT 1
                         FROM pg_user AS u3,
                              pg_attribute AS a3,
                              pg_class AS c3
                         WHERE u3.usesysid = c3.relowner
                           AND a3.attrelid = c3.oid
                           AND a3.atttypid = t.oid));


GRANT SELECT ON domains TO PUBLIC;


/*
 * 20.35
 * REFERENTIAL_CONSTRAINTS view
 */

CREATE VIEW referential_constraints AS
    SELECT CAST(current_database() AS sql_identifier) AS constraint_catalog,
           CAST(ncon.nspname AS sql_identifier) AS constraint_schema,
           CAST(con.conname AS sql_identifier) AS constraint_name,
           CAST(current_database() AS sql_identifier) AS unique_constraint_catalog,
           CAST(null AS sql_identifier) AS unique_constraint_schema, -- XXX
           CAST(null AS sql_identifier) AS unique_constraint_name, -- XXX

           CAST(
             CASE con.confmatchtype WHEN 'f' THEN 'FULL'
                                    WHEN 'p' THEN 'PARTIAL'
                                    WHEN 'u' THEN 'NONE' END
             AS character_data) AS match_option,

           CAST(
             CASE con.confupdtype WHEN 'c' THEN 'CASCADE'
                                  WHEN 'n' THEN 'SET NULL'
                                  WHEN 'd' THEN 'SET DEFAULT'
                                  WHEN 'r' THEN 'RESTRICT'
                                  WHEN 'a' THEN 'NOACTION' END
             AS character_data) AS update_rule,

           CAST(
             CASE con.confdeltype WHEN 'c' THEN 'CASCADE'
                                  WHEN 'n' THEN 'SET NULL'
                                  WHEN 'd' THEN 'SET DEFAULT'
                                  WHEN 'r' THEN 'RESTRICT'
                                  WHEN 'a' THEN 'NOACTION' END
             AS character_data) AS delete_rule

    FROM pg_namespace ncon,
         pg_constraint con,
         pg_class r,
         pg_user u

    WHERE ncon.oid = con.connamespace
          AND con.conrelid = r.oid AND r.relowner = u.usesysid
          AND u.usename = current_user;

GRANT SELECT ON referential_constraints TO PUBLIC;


/*
 * 20.46
 * SCHEMATA view
 */

CREATE VIEW schemata AS
    SELECT CAST(current_database() AS sql_identifier) AS catalog_name,
           CAST(n.nspname AS sql_identifier) AS schema_name,
           CAST(u.usename AS sql_identifier) AS schema_owner,
           CAST(null AS sql_identifier) AS default_character_set_catalog,
           CAST(null AS sql_identifier) AS default_character_set_schema,
           CAST(null AS sql_identifier) AS default_character_set_name,
           CAST(null AS character_data) AS sql_path
    FROM pg_namespace n, pg_user u
    WHERE n.nspowner = u.usesysid AND u.usename = current_user;

GRANT SELECT ON schemata TO PUBLIC;


/*
 * 20.47
 * SQL_FEATURES table
 */

CREATE TABLE sql_features (
    feature_id          character_data,
    feature_name        character_data,
    sub_feature_id      character_data,
    sub_feature_name    character_data,
    is_supported        character_data,
    is_verified_by      character_data,
    comments            character_data
) WITHOUT OIDS;

-- Will be filled with external data by initdb.

GRANT SELECT ON sql_features TO PUBLIC;


/*
 * 20.48
 * SQL_IMPLEMENTATION_INFO table
 */

-- Note: Implementation information items are defined in ISO 9075-3:1999,
-- clause 7.1.

CREATE TABLE sql_implementation_info (
    implementation_info_id      character_data,
    implementation_info_name    character_data,
    integer_value               cardinal_number,
    character_value             character_data,
    comments                    character_data
) WITHOUT OIDS;

INSERT INTO sql_implementation_info VALUES ('10003', 'CATALOG NAME', NULL, 'Y', NULL);
INSERT INTO sql_implementation_info VALUES ('10004', 'COLLATING SEQUENCE', NULL, '', 'not supported');
INSERT INTO sql_implementation_info VALUES ('23',    'CURSOR COMMIT BEHAVIOR', 1, NULL, 'close cursors and retain prepared statements');
INSERT INTO sql_implementation_info VALUES ('2',     'DATA SOURCE NAME', NULL, '', NULL);
INSERT INTO sql_implementation_info VALUES ('17',    'DBMS NAME', NULL, (select trim(trailing ' ' from substring(version() from '^[^0-9]*'))), NULL);
INSERT INTO sql_implementation_info VALUES ('18',    'DBMS VERSION', NULL, '???', NULL); -- filled by initdb
INSERT INTO sql_implementation_info VALUES ('26',    'DEFAULT TRANSACTION ISOLATION', 2, NULL, 'READ COMMITED; user-settable');
INSERT INTO sql_implementation_info VALUES ('28',    'IDENTIFIER CASE', 3, NULL, 'stored in mixed case - case sensitive');
INSERT INTO sql_implementation_info VALUES ('85',    'NULL COLLATION', 0, NULL, 'nulls higher than non-nulls');
INSERT INTO sql_implementation_info VALUES ('13',    'SERVER NAME', NULL, '', NULL);
INSERT INTO sql_implementation_info VALUES ('94',    'SPECIAL CHARACTERS', NULL, '', 'all non-ASCII characters allowed');
INSERT INTO sql_implementation_info VALUES ('46',    'TRANSACTION CAPABLE', 2, NULL, 'both DML and DDL');

GRANT SELECT ON sql_implementation_info TO PUBLIC;


/*
 * 20.49
 * SQL_LANGUAGES table
 */

CREATE TABLE sql_languages (
    sql_language_source         character_data,
    sql_language_year           character_data,
    sql_language_conformance    character_data,
    sql_language_integrity      character_data,
    sql_language_implementation character_data,
    sql_language_binding_style  character_data,
    sql_language_programming_language character_data
) WITHOUT OIDS;

INSERT INTO sql_languages VALUES ('ISO 9075', '1999', 'CORE', NULL, NULL, 'DIRECT', NULL);
INSERT INTO sql_languages VALUES ('ISO 9075', '1999', 'CORE', NULL, NULL, 'EMBEDDED', 'C');

GRANT SELECT ON sql_languages TO PUBLIC;


/*
 * 20.50
 * SQL_PACKAGES table
 */

CREATE TABLE sql_packages (
    feature_id      character_data,
    feature_name    character_data,
    is_supported    character_data,
    is_verified_by  character_data,
    comments        character_data
) WITHOUT OIDS;

INSERT INTO sql_packages VALUES ('PKG000', 'Core', 'NO', NULL, '');
INSERT INTO sql_packages VALUES ('PKG001', 'Enhanced datetime facilities', 'YES', NULL, '');
INSERT INTO sql_packages VALUES ('PKG002', 'Enhanced integrity management', 'NO', NULL, '');
INSERT INTO sql_packages VALUES ('PKG003', 'OLAP facilities', 'NO', NULL, '');
INSERT INTO sql_packages VALUES ('PKG004', 'PSM', 'NO', NULL, 'PL/pgSQL is similar.');
INSERT INTO sql_packages VALUES ('PKG005', 'CLI', 'NO', NULL, 'ODBC is similar.');
INSERT INTO sql_packages VALUES ('PKG006', 'Basic object support', 'NO', NULL, '');
INSERT INTO sql_packages VALUES ('PKG007', 'Enhanced object support', 'NO', NULL, '');
INSERT INTO sql_packages VALUES ('PKG008', 'Active database', 'NO', NULL, '');
INSERT INTO sql_packages VALUES ('PKG009', 'SQL/MM support', 'NO', NULL, '');

GRANT SELECT ON sql_packages TO PUBLIC;


/*
 * 20.51
 * SQL_SIZING table
 */

-- Note: Sizing items are defined in ISO 9075-3:1999, clause 7.2.

CREATE TABLE sql_sizing (
    sizing_id       cardinal_number,
    sizing_name     character_data,
    supported_value cardinal_number,
    comments        character_data
) WITHOUT OIDS;

INSERT INTO sql_sizing VALUES (34,    'MAXIMUM CATALOG NAME LENGTH', 63, NULL);
INSERT INTO sql_sizing VALUES (30,    'MAXIMUM COLUMN NAME LENGTH', 63, NULL);
INSERT INTO sql_sizing VALUES (97,    'MAXIMUM COLUMNS IN GROUP BY', 0, NULL);
INSERT INTO sql_sizing VALUES (99,    'MAXIMUM COLUMNS IN ORDER BY', 0, NULL);
INSERT INTO sql_sizing VALUES (100,   'MAXIMUM COLUMNS IN SELECT', 0, NULL);
INSERT INTO sql_sizing VALUES (101,   'MAXIMUM COLUMNS IN TABLE', 1600, NULL); -- match MaxHeapAttributeNumber
INSERT INTO sql_sizing VALUES (1,     'MAXIMUM CONCURRENT ACTIVITIES', 0, NULL);
INSERT INTO sql_sizing VALUES (31,    'MAXIMUM CURSOR NAME LENGTH', 63, NULL);
INSERT INTO sql_sizing VALUES (0,     'MAXIMUM DRIVER CONNECTIONS', NULL, NULL);
INSERT INTO sql_sizing VALUES (10005, 'MAXIMUM IDENTIFIER LENGTH', 63, NULL);
INSERT INTO sql_sizing VALUES (32,    'MAXIMUM SCHEMA NAME LENGTH', 63, NULL);
INSERT INTO sql_sizing VALUES (20000, 'MAXIMUM STATEMENT OCTETS', 0, NULL);
INSERT INTO sql_sizing VALUES (20001, 'MAXIMUM STATEMENT OCTETS DATA', 0, NULL);
INSERT INTO sql_sizing VALUES (20002, 'MAXIMUM STATEMENT OCTETS SCHEMA', 0, NULL);
INSERT INTO sql_sizing VALUES (35,    'MAXIMUM TABLE NAME LENGTH', 63, NULL);
INSERT INTO sql_sizing VALUES (106,   'MAXIMUM TABLES IN SELECT', 0, NULL);
INSERT INTO sql_sizing VALUES (107,   'MAXIMUM USER NAME LENGTH', 63, NULL);
INSERT INTO sql_sizing VALUES (25000, 'MAXIMUM CURRENT DEFAULT TRANSFORM GROUP LENGTH', NULL, NULL);
INSERT INTO sql_sizing VALUES (25001, 'MAXIMUM CURRENT TRANSFORM GROUP LENGTH', NULL, NULL);
INSERT INTO sql_sizing VALUES (25002, 'MAXIMUM CURRENT PATH LENGTH', 0, NULL);
INSERT INTO sql_sizing VALUES (25003, 'MAXIMUM CURRENT ROLE LENGTH', NULL, NULL);
INSERT INTO sql_sizing VALUES (25004, 'MAXIMUM SESSION USER LENGTH', 63, NULL);
INSERT INTO sql_sizing VALUES (25005, 'MAXIMUM SYSTEM USER LENGTH', 63, NULL);

UPDATE sql_sizing
    SET supported_value = (SELECT typlen-1 FROM pg_catalog.pg_type WHERE typname = 'name'),
        comments = 'Might be less, depending on character set.'
    WHERE supported_value = 63;

GRANT SELECT ON sql_sizing TO PUBLIC;


/*
 * 20.52
 * SQL_SIZING_PROFILES table
 */

-- The data in this table are defined by various profiles of SQL.
-- Since we don't have any information about such profiles, we provide
-- an empty table.

CREATE TABLE sql_sizing_profiles (
    sizing_id       cardinal_number,
    sizing_name     character_data,
    profile_id      character_data,
    required_value  cardinal_number,
    comments        character_data
) WITHOUT OIDS;

GRANT SELECT ON sql_sizing_profiles TO PUBLIC;


/*
 * 20.53
 * TABLE_CONSTRAINTS view
 */

CREATE VIEW table_constraints AS
    SELECT CAST(current_database() AS sql_identifier) AS constraint_catalog,
           CAST(nc.nspname AS sql_identifier) AS constraint_schema,
           CAST(c.conname AS sql_identifier) AS constraint_name,
           CAST(current_database() AS sql_identifier) AS table_catalog,
           CAST(nr.nspname AS sql_identifier) AS table_schema,
           CAST(r.relname AS sql_identifier) AS table_name,
           CAST(
             CASE c.contype WHEN 'c' THEN 'CHECK'
                            WHEN 'f' THEN 'FOREIGN KEY'
                            WHEN 'p' THEN 'PRIMARY KEY'
                            WHEN 'u' THEN 'UNIQUE' END
             AS character_data) AS constraint_type,
           CAST(CASE WHEN c.condeferrable THEN 'YES' ELSE 'NO' END AS character_data)
             AS is_deferrable,
           CAST(CASE WHEN c.condeferred THEN 'YES' ELSE 'NO' END AS character_data)
             AS initially_deferred

    FROM pg_namespace nc,
         pg_namespace nr,
         pg_constraint c,
         pg_class r,
         pg_user u

    WHERE nc.oid = c.connamespace AND nr.oid = r.relnamespace
          AND c.conrelid = r.oid AND r.relowner = u.usesysid
          AND u.usename = current_user;

-- FIMXE: Not-null constraints are missing here.

GRANT SELECT ON table_constraints TO PUBLIC;


/*
 * 20.55
 * TABLE_PRIVILEGES view
 */

CREATE VIEW table_privileges AS
    SELECT CAST(u_owner.usename AS sql_identifier) AS grantor,
           CAST(u_grantee.usename AS sql_identifier) AS grantee,
           CAST(current_database() AS sql_identifier) AS table_catalog,
           CAST(nc.nspname AS sql_identifier) AS table_schema,
           CAST(c.relname AS sql_identifier) AS table_name,
           CAST(pr.type AS character_data) AS privilege_type,
           CAST('NO' AS character_data) AS is_grantable,
           CAST('NO' AS character_data) AS with_hierarchy

    FROM pg_user u_owner,
         pg_user u_grantee,
         pg_namespace nc,
         pg_class c,
         (SELECT 'SELECT' UNION SELECT 'DELETE' UNION SELECT 'INSERT' UNION SELECT 'UPDATE'
          UNION SELECT 'REFERENCES' UNION SELECT 'TRIGGER') AS pr (type)

    WHERE u_owner.usesysid = c.relowner
          AND c.relnamespace = nc.oid
          AND has_table_privilege(u_grantee.usename, c.oid, pr.type)

          AND (u_owner.usename = current_user OR u_grantee.usename = current_user);

GRANT SELECT ON table_privileges TO PUBLIC;


/*
 * 20.56
 * TABLES view
 */

CREATE VIEW tables AS
    SELECT CAST(current_database() AS sql_identifier) AS table_catalog,
           CAST(nc.nspname AS sql_identifier) AS table_schema,
           CAST(c.relname AS sql_identifier) AS table_name,

           CAST(
             CASE WHEN nc.nspname LIKE 'pg!_temp!_%' ESCAPE '!' THEN 'LOCAL TEMPORARY'
                  WHEN c.relkind = 'r' THEN 'BASE TABLE'
                  WHEN c.relkind = 'v' THEN 'VIEW'
                  ELSE null END
             AS character_data) AS table_type,

           CAST(null AS sql_identifier) AS self_referencing_column_name,
           CAST(null AS character_data) AS reference_generation,

           CAST(null AS sql_identifier) AS user_defined_type_catalog,
           CAST(null AS sql_identifier) AS user_defined_type_schema,
           CAST(null AS sql_identifier) AS user_defined_name

    FROM pg_namespace nc, pg_class c, pg_user u

    WHERE c.relnamespace = nc.oid AND u.usesysid = c.relowner
          AND (u.usename = current_user
               OR EXISTS(SELECT 1 FROM information_schema.table_privileges tp
                                  WHERE tp.table_schema = nc.nspname
                                        AND tp.table_name = c.relname
                                        AND tp.grantee = current_user))

          AND c.relkind IN ('r', 'v');

GRANT SELECT ON tables TO PUBLIC;


/*
 * 20.63
 * USAGE_PRIVILEGES view
 */

-- Of the things currently implemented in PostgreSQL, usage privileges
-- apply only to domains.  Since domains have no real privileges, we
-- represent all domains with implicit usage privilege here.

CREATE VIEW usage_privileges AS
    SELECT CAST(u.usename AS sql_identifier) AS grantor,
           CAST('PUBLIC' AS sql_identifier) AS grantee,
           CAST(current_database() AS sql_identifier) AS object_catalog,
           CAST(n.nspname AS sql_identifier) AS object_schema,
           CAST(t.typname AS sql_identifier) AS object_name,
           CAST('DOMAIN' AS character_data) AS object_type,
           CAST('USAGE' AS character_data) AS privilege_type,
           CAST('NO' AS character_data) AS is_grantable

    FROM pg_user u,
         pg_namespace n,
         pg_type t

    WHERE u.usesysid = t.typowner
          AND t.typnamespace = n.oid
          AND t.typtype = 'd';

GRANT SELECT ON usage_privileges TO PUBLIC;


/*
 * 20.68
 * VIEWS view
 */

CREATE VIEW views AS
    SELECT CAST(current_database() AS sql_identifier) AS table_catalog,
           CAST(nc.nspname AS sql_identifier) AS table_schema,
           CAST(c.relname AS sql_identifier) AS table_name,

           CAST(
             CASE WHEN u.usename = current_user THEN pg_get_viewdef(c.oid)
                  ELSE null END
             AS character_data) AS view_definition,

           CAST('NONE' AS character_data) AS check_option,
           CAST(null AS character_data) AS is_updatable, -- FIXME
           CAST(null AS character_data) AS is_insertable_into  -- FIXME

    FROM pg_namespace nc, pg_class c, pg_user u

    WHERE c.relnamespace = nc.oid AND u.usesysid = c.relowner
          AND (u.usename = current_user
               OR EXISTS(SELECT 1 FROM information_schema.table_privileges tp
                                  WHERE tp.table_schema = nc.nspname
                                        AND tp.table_name = c.relname
                                        AND tp.grantee = current_user))

          AND c.relkind = 'v';

GRANT SELECT ON views TO PUBLIC;