Improve isc_blob_info [+ isc_info_blob_char_length] [CORE1535]

[firebird-automations]

Submitted by: @ibprovider

Votes: 1

Target: optimization of Firebird work as MSSQL linked server

MSSQL get BLOB text data in two steps:
- Get count of characters
- Get text

Currently, for multi-byte BLOB text (UNICODE_FSS / UTF8), we can't calculate count of characters without load of all BLOB on client side.

I think, this operation can be maked on server side.

For this we can define new command isc_info_blob_char_length for IB API function isc_blob_info

First time isc_info_blob_char_length must simple calculate character count (with minimum optimization for single-byte code page)

In future you can change ODS and store prepared char length of text BLOB

---
I hope, you implement this feature in FB 2.1, because (i think) this do not required very hard work. And their effect - very very large.

[firebird-automations]

Commented by: @asfernandes

You can use CHAR_LENGTH SQL function with blobs.

[firebird-automations]

Commented by: @ibprovider

And instead of isc_info_blob_total_length I can use OCTET_LENGTH?

Incorrect answer.

Using any SQL - 3 call of server (execute,fetch,close) as minimum

Using of isc_info_blob_xxx - one (?) call only

[firebird-automations]

Modified by: @pcisar

Workflow: jira [ 13341 ] => Firebird [ 14020 ]