Re: Storage: upsert vs. delete + insert

2014-09-10 Thread graham sanderson
agreed On Sep 10, 2014, at 3:27 PM, olek.stas...@gmail.com wrote: > You're right, there is no data in tombstone, only a column name. So > there is only small overhead of disk size after delete. But i must > agree with post above, it's pointless in deleting prior to inserting. > Moreover, it needs

Re: Storage: upsert vs. delete + insert

2014-09-10 Thread olek.stas...@gmail.com
You're right, there is no data in tombstone, only a column name. So there is only small overhead of disk size after delete. But i must agree with post above, it's pointless in deleting prior to inserting. Moreover, it needs one op more to compute resulting row. cheers, Olek 2014-09-10 22:18 GMT+02

Re: Storage: upsert vs. delete + insert

2014-09-10 Thread graham sanderson
delete inserts a tombstone which is likely smaller than the original record (though still (currently) has overhead of cost for full key/column name the data for the insert after a delete would be identical to the data if you just inserted/updated no real benefit I can think of for doing the dele

Re: Storage: upsert vs. delete + insert

2014-09-10 Thread olek.stas...@gmail.com
I think so. this is how i see it: on the very beginning you have such line in datafile: {key: [col_name, col_value, date_of_last_change]} //something similar, i don't remember now after delete you're adding line: {key:[col_name, last_col_value, date_of_delete, 'd']} //this d indicates that field i

Re: Storage: upsert vs. delete + insert

2014-09-10 Thread Michal Budzyn
Would the factor before compaction be always 2 ? On Wed, Sep 10, 2014 at 6:38 PM, olek.stas...@gmail.com < olek.stas...@gmail.com> wrote: > IMHO, delete then insert will take two times more disk space then > single insert. But after compaction the difference will disappear. > This was true in ver

Re: Storage: upsert vs. delete + insert

2014-09-10 Thread olek.stas...@gmail.com
IMHO, delete then insert will take two times more disk space then single insert. But after compaction the difference will disappear. This was true in version prior to 2.0, but it should still work this way. But maybe someone will correct me, if i'm wrong. Cheers, Olek 2014-09-10 18:30 GMT+02:00 Mi

Re: Storage: upsert vs. delete + insert

2014-09-10 Thread Michal Budzyn
One insert would be much better e.g. for performance and network latency. I wanted to know if there is a significant difference (apart from additional commit log entry) in the used storage between these 2 use cases.

Re: Storage: upsert vs. delete + insert

2014-09-10 Thread Shane Hansen
My understanding is that a update is the same as an insert. So I would think delete+insert is a bad idea. Also insert+delete would put 2 entries in the commit log. On Sep 10, 2014 9:49 AM, "Michal Budzyn" wrote: > Is there any serious difference in the used disk and memory storage > between upser

Storage: upsert vs. delete + insert

2014-09-10 Thread Michal Budzyn
Is there any serious difference in the used disk and memory storage between upsert and delete + insert ? e.g. 2 vs 2A + 2B. PK ((key), version, c1) 1. INSERT INTO A (key , version , c1, val) values (1, 1, 4711, “X1”) ... 2. INSERT INTO A (key , version , c1, val) values (1, 1, 4711, “X2”) Vs. 2A