Oracle - 仅在不存在时创建索引

Question

只有当索引不存在时，有没有办法在 oracle 中创建索引？

就像是

CREATE INDEX IF NOT EXISTS ord_customer_ix
   ON orders (customer_id);

Answer 1

仅在不存在时添加索引:

declare 
  already_exists  exception; 
  columns_indexed exception;
  pragma exception_init( already_exists, -955 ); 
  pragma exception_init(columns_indexed, -1408);
begin 
  execute immediate 'create index ord_customer_ix on orders (customer_id)'; 
  dbms_output.put_line( 'created' ); 
exception 
  when already_exists or columns_indexed then 
  dbms_output.put_line( 'skipped' );  
end;