Ошибки при создании метаданных

При создании метаданных (таблицы, тригеры, домены и т.д.) мы можем получить ошибки которые будут не очень понятны начинающему пользователю

Создание индекса с существующим именем

CREATE INDEX COUNTRY_IDX1 ON COUNTRY (CURRENCY);
CREATE INDEX COUNTRY_IDX1 ON COUNTRY (CURRENCY);

This operation is not defined for system tables.
unsuccessful metadata update.
STORE RDB$INDICES failed.
attempt to store duplicate value (visible to active transactions) in unique index «RDB$INDEX_5».

Создание генератора с существующим именем

CREATE generator test;
CREATE generator test;

This operation is not defined for system tables.
unsuccessful metadata update.
DEFINE GENERATOR failed.
attempt to store duplicate value (visible to active transactions) in unique index «RDB$INDEX_11».

Создание таблицы с одноименными полями

CREATE TABLE test(x INT, x VARCHAR(30));

This operation is not defined for system tables.
unsuccessful metadata update.
STORE RDB$RELATION_FIELDS failed.
attempt to store duplicate value (visible to active transactions) in unique index «RDB$INDEX_15».

Создание процедуры с одноименными полями

CREATE PROCEDURE test (t INT) RETURNS (t VARCHAR(30))
AS 
BEGIN
END;

This operation is not defined for system tables.
unsuccessful metadata update.
STORE RDB$PROCEDURE_PARAMETERS failed.
attempt to store duplicate value (visible to active transactions) in unique index «RDB$INDEX_18».

Создание домена с существующим именем

CREATE DOMAIN test SMALLINT;
CREATE DOMAIN test SMALLINT;

This operation is not defined for system tables.
unsuccessful metadata update.
STORE RDB$FIELDS failed.
attempt to store duplicate value (visible to active transactions) in unique index «RDB$INDEX_2».

Создание триггера с существующим именем

CREATE TRIGGER country_bi0 FOR country
active BEFORE INSERT POSITION 0
AS
BEGIN
  /* Trigger text */
END;
CREATE TRIGGER country_bi0 FOR country
active BEFORE INSERT POSITION 0
AS
BEGIN
  /* Trigger text */
END;

This operation is not defined for system tables.
unsuccessful metadata update.
DEFINE TRIGGER failed.
attempt to store duplicate value (visible to active transactions) in unique index «RDB$INDEX_8».

Создание UDF с существующим именем

DECLARE EXTERNAL FUNCTION DIV
    INTEGER,
    INTEGER
RETURNS DOUBLE PRECISION BY VALUE
ENTRY_POINT 'IB_UDF_div' MODULE_NAME 'ib_udf';
DECLARE EXTERNAL FUNCTION DIV
    INTEGER,
    INTEGER
RETURNS DOUBLE PRECISION BY VALUE
ENTRY_POINT 'IB_UDF_div' MODULE_NAME 'ib_udf';

This operation is not defined for system tables.
unsuccessful metadata update.
DEFINE FUNCTION failed.
attempt to store duplicate value (visible to active transactions) in unique index «RDB$INDEX_9».