OCI-11557
IF EXISTS clause cannot be used with the current DDL
Cause
IF EXISTS clause cannot be used with DDL statements that may move data, DDLs that recompile a materialized view, DDLs that alter an index or DDLs that drop a private temporary table. Examples: ALTER TABLE table ADD|DROP PARTITION ... ALTER TABLE table COALESCE PARTITION ... ALTER TABLE table MOVE ... ALTER MATERIALIZED VIEW <mat_view> MERGE PARTITIONS ... ALTER MATERIALIZED VIEW <mat_view> COMPILE ... ALTER INDEX index ... DROP TEMPORARY TABLE ... Please check the documentation for a list of DDL statements that are not supported.
Action
Do not use IF EXISTS clause for this DDL statement.