I'll provide it to, bear with me, pls... Best regards. -- WB
2010/11/30 Johan De Meersman <vegiv...@tuxera.be> > Interesting, but I feel the difference is rather small - could you rerun > with, say, 50.000 queries ? Also, different concurrency levels (1, 100) > might be interesting to see. > > Yes, I'm to lazy to do it myself, what did you think :-p > > > On Tue, Nov 30, 2010 at 4:01 PM, Wagner Bianchi <wagnerbianch...@gmail.com > > wrote: > >> Friends, I did a benchmark regarding to this subject. >> Please, I am considering your comments. >> => http://wbianchi.wordpress.com/2010/11/30/insert-x-insert-delayed/ >> >> Best regards. >> -- >> WB >> >> >> 2010/11/30 Wagner Bianchi <wagnerbianch...@gmail.com> >> >> Maybe, the table in use must be a table that is inside cache now - SHOW >>> OPEN TABLES, controlled by table_cache, I mean. >>> >>> Well, if the amount of data trasactioned is too small as a simple INSERT, >>> you don't have to be worried, I suggest. If you partition the table, we must >>> a benchmark to know the performance relation of a INSERT and compress data >>> into Archive Storage Engine or the insertion data into a partitioned table. >>> >>> Best regards. >>> -- >>> WB >>> >>> >>> 2010/11/30 Johan De Meersman <vegiv...@tuxera.be> >>> >>> I would assume that it's slower because it gets put on the delay thread >>>> anyway, and thus executes only whenever that thread gets some attention. >>>> I'm >>>> not sure wether there are other influencing factors. >>>> >>>> I should also think that "not in use" in this context means "not locked >>>> against inserts", so the MyISAM insert-while-selecting at the end of a >>>> continguous table may well apply. >>>> >>>> No guarantees, though - I'm not that hot on this depth. >>>> >>>> >>>> >>>> On Tue, Nov 30, 2010 at 8:46 AM, WLGades <wlga...@gmail.com> wrote: >>>> >>>>> What I'm confused by though, is this line. >>>>> >>>>> "Note that INSERT DELAYED is slower than a normal INSERT if the table >>>>> is not >>>>> otherwise in use." What's the definition of "in use"? Does a logging >>>>> table >>>>> do that given that it's pretty much append-only/write-only? >>>>> >>>>> Waynn >>>>> >>>>> On Mon, Nov 29, 2010 at 10:19 PM, Johan De Meersman < >>>>> vegiv...@tuxera.be>wrote: >>>>> >>>>> > No, I think it's a good idea to do INSERT DELAYED here - it's only >>>>> logging >>>>> > application, and it's generally more important to not slow down the >>>>> > application for that. It's only ever into a single table, so there's >>>>> only >>>>> > going to be a single delay thread for it anyway. >>>>> > >>>>> > Archive tables are a good idea, agreed, but I suspect that inserts >>>>> into >>>>> > that are going to be slower than into regular MyISAM because of the >>>>> > compression, so why not use that overhead to (slightly) speed up your >>>>> > end-user experience instead ? >>>>> > >>>>> > You can always partition the table based on the log date or whatever, >>>>> if >>>>> > your table risks getting too big. >>>>> > >>>>> > >>>>> > >>>>> > On Tue, Nov 30, 2010 at 1:03 AM, Wagner Bianchi < >>>>> wagnerbianch...@gmail.com >>>>> > > wrote: >>>>> > >>>>> >> Well, analyze if you need to create an excessive overhead into the >>>>> MySQL >>>>> >> Server because a simple INSERT. What you must have a look is it: >>>>> >> >>>>> >> - How much data this connection is delivering to MySQL's handlers? >>>>> >> - A word DELAYED in this case is making MySQL surfer? >>>>> >> >>>>> >> Perhaps, you are sophisticating something that do not need it. >>>>> Besides it, >>>>> >> analyzing your "log table", I imagine this table can be an Archive >>>>> table >>>>> >> instead of MyISAM. Log tables or history tables can be controlled by >>>>> >> Archive >>>>> >> Storage Engine to have more compressed data. Although, Archive >>>>> Storage >>>>> >> Engine only supports SELECT and INSERT. Maybe, a good deal to you, >>>>> get rid >>>>> >> of you INSERT DELAYED: >>>>> >> >>>>> >> >>>>> >> - ALTER TABLE <tbl_name> ENGINE = ARCHIVE; >>>>> >> >>>>> >> >>>>> >> Best regards. >>>>> >> -- >>>>> >> WB >>>>> >> >>>>> >> >>>>> >> 2010/11/29 WLGades <wlga...@gmail.com> >>>>> >> >>>>> >> > I'm adding a table to our site that logs all page loads. In the >>>>> past, >>>>> >> when >>>>> >> > I built this, I used MyISAM and INSERT DELAYED. I went back to >>>>> look at >>>>> >> the >>>>> >> > documentation to see if I should still do this, and saw this >>>>> (taken from >>>>> >> > http://dev.mysql.com/doc/refman/5.1/en/insert-delayed.html): >>>>> >> > >>>>> >> > Note that INSERT DELAYED is slower than a normal INSERT if the >>>>> table is >>>>> >> not >>>>> >> > otherwise in use. There is also the additional overhead for the >>>>> server >>>>> >> to >>>>> >> > handle a separate thread for each table for which there are >>>>> delayed >>>>> >> rows. >>>>> >> > This means that you should use INSERT DELAYED only when you are >>>>> really >>>>> >> sure >>>>> >> > that you need it. >>>>> >> > >>>>> >> > Does that mean that I shouldn't use it if all I'm doing is INSERT >>>>> >> > (essentially an append-only table), with only very occasional >>>>> SELECTs? >>>>> >> In >>>>> >> > addition, the last time I took this approach for logging, it >>>>> worked well >>>>> >> > until the table got to 65M+ rows, when it would crash every now >>>>> and >>>>> >> then. >>>>> >> > I >>>>> >> > know I can archive off the table on a per month/quarter basis as >>>>> well. >>>>> >> > >>>>> >> > Waynn >>>>> >> > >>>>> >> >>>>> > >>>>> > >>>>> > >>>>> > -- >>>>> > Bier met grenadyn >>>>> > Is als mosterd by den wyn >>>>> > Sy die't drinkt, is eene kwezel >>>>> > Hy die't drinkt, is ras een ezel >>>>> > >>>>> >>>> >>>> >>>> >>>> -- >>>> Bier met grenadyn >>>> Is als mosterd by den wyn >>>> Sy die't drinkt, is eene kwezel >>>> Hy die't drinkt, is ras een ezel >>>> >>> >>> >> > > > -- > Bier met grenadyn > Is als mosterd by den wyn > Sy die't drinkt, is eene kwezel > Hy die't drinkt, is ras een ezel >
