feat: add support for encode&decode

[BanBuDu0]

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What's changed and what's your intention?

According to #8937.
The encode and decode function are implemented in this pull request.

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Release note

[lmatz]

Could you help enable the test cases here:

risingwave/src/tests/regress/data/sql/strings.sql

Line 649 in 0bdc988

-- encode/decode

[BanBuDu0]

SELECT encode(('\x' || repeat('1234567890abcdef0001', 7))::bytea, 'base64');
SELECT decode(encode(('\x' || repeat('1234567890abcdef0001', 7))::bytea, 'base64'), 'base64');
These two sqls will produce an error:
ERROR: QueryError: Bind error: cannot cast type "varchar" to "bytea" in Explicit context

Seems like an error happend in compile-time which cast expr bind error.
I see that no Bytea type mentioned in CAST_MAP https://github.com/risingwavelabs/risingwave/blob/main/src/expr/src/sig/cast.rs#L51

[BanBuDu0]

SELECT encode(('\x' || repeat('1234567890abcdef0001', 7))::bytea, 'base64'); SELECT decode(encode(('\x' || repeat('1234567890abcdef0001', 7))::bytea, 'base64'), 'base64'); These two sqls will produce an error: ERROR: QueryError: Bind error: cannot cast type "varchar" to "bytea" in Explicit context

Seems like an error happend in compile-time which cast expr bind error. I see that no Bytea type mentioned in CAST_MAP https://github.com/risingwavelabs/risingwave/blob/main/src/expr/src/sig/cast.rs#L51

I see that the cast function [varchar->bytea] was already implemented here https://github.com/risingwavelabs/risingwave/blob/main/src/expr/src/vector_op/cast.rs#L196

So I fix it by simple add Bytea type to CAST_MAP, see commit：432b705
Is there something wrong with this fix?

[xiangjinwu]

Thanks for your contribution. And your fix to the CAST_MAP is correct.

[BanBuDu0]

After I changed the CAST_MAP, I should also modify the e2e_test/batch/catalog/pg_cast.slt.part, which the catalog was
following the changes of CAST_MAP.
By the way, I also fixed the from_oid function here https://github.com/risingwavelabs/risingwave/blob/main/src/common/src/types/postgres_type.rs#L48, there was no Bytea before.
See 186bc93

Finally, all the test was passsed now🥳.

[lmatz]

Many thanks for your contribution!