AWS Redshift：卸载时错误转义

Question

我在卸载特定文本时发现错误的逃脱。

当文本的(为最后一个字符时，请按照下面的方式转义。

# expected
"hoge","huga","longtext (","2016-01-01"

# actual
"hoge","huga","longtext (\,"2016-01-01"

要卸载的查询是

UNLOAD ( ${SELECT_STATEMENT} )
TO 's3:// ${S3_PATH} '
CREDENTIALS 'aws_access_key_id= ${ACCESS_KEY_ID} ;aws_secret_access_key= ${ACCESS_KEY} '
DELIMITER ','
ALLOWOVERWRITE
ESCAPE
ADDQUOTES

你知道如何避免这个问题吗？