[MCOL-643] support longer then 8m rows in order by Created: 2017-03-28  Updated: 2023-11-17  Resolved: 2023-10-25

Status: Closed
Project: MariaDB ColumnStore
Component/s: Columnstore Select Handler
Affects Version/s: 1.1.0
Fix Version/s: Icebox

Type: New Feature Priority: Minor
Reporter: Andrew Hutchings (Inactive) Assignee: Todd Stoffel (Inactive)
Resolution: Won't Fix Votes: 3
Labels: triage

Issue Links:
Duplicate
is duplicated by MCOL-4735 Length may not exceed 8000 for utf8 v... Closed
Relates
relates to MCOL-3879 ExeMgr crash on select - SELECT TABLE... Closed
relates to MCOL-267 TEXT and BLOB data types are not supp... Closed
relates to MDEV-14500 filesort to support engines with slow... Closed
Epic Link: ColumnStore Compatibility Improvements
Sprint: 2017-7, 2017-8, 2017-15, 2017-16, 2017-17, 2017-18

 Description   

Without ha_calpont_impl_rnd_pos we are limited to a maximum of 8MB row length including blobs for sorting. For 1.0 this was fine but with BLOB/TEXT support this may not be enough.

At the moment this function just returns the following error message:

Sorting length exceeded. Session variable max_length_for_sort_data needs to be set higher.



 Comments   
Comment by Andrew Hutchings (Inactive) [ 2017-05-11 ]

Parts of what we need are already implemented. sm.cpp has code to save results into band files which can then be read back. We need random read to use SAVING and SAVED states.

Comment by Andrew Hutchings (Inactive) [ 2017-11-27 ]

Added related issue MDEV-14500 which could eliminate the need for this.

In addition we could just use block/offset pointers and request those from PrimProc instead of using a disk cache of the result set.

Comment by Andrew Hutchings (Inactive) [ 2020-01-31 ]

There are other reasons to implement this, but the original problem is solved in 1.4

Comment by Valerii Kravchuk [ 2021-08-28 ]

Can we get any status update here? Do we still have any need to implement this feature in 10.6/Columnstore 6.x.y?

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