From: Alexander Turenko <alexander.turenko@tarantool.org> To: Nikita Tatunov <hollow653@gmail.com> Cc: tarantool-patches@freelists.org Subject: [tarantool-patches] Re: [PATCH] sql: xfer optimization issue Date: Sun, 29 Jul 2018 04:12:51 +0300 [thread overview] Message-ID: <20180729011251.eitp7cisv6jv5opj@tkn_work_nb> (raw) In-Reply-To: <CAEi+_ap4Lc5QBPExitzSt_ZDMbF3ea=iqXFLGXDvwV+rY1MQ=Q@mail.gmail.com> Hi! Please consider my comments and questions below. WBR, Alexander Turenko. > + /* > + * Xfer optimization is unable to correctly insert data > + * in case there's a conflict action other than > + * explicit *_ABORT. This is the reason we want to only > + * run it if the destination table is initially empty. > + * That block generates code to make that determination. > + */ > + if (!(onError == ON_CONFLICT_ACTION_ABORT && > + !is_err_action_default)) { Do you mean that: 1. The optimization non-empty table case correctly works only with ABORT conflict action (default or explicit). 2. The default conflict action can be overwritten on per-column basis, so 'default abort' can really be replace or other conflict action. If so, your description doesn't give this information. To more on that, can we check per-column conflict actions instead of check whether the conflict action default or explicit? This would enable more cases with non-empty tables for the optimization. And this would look less confusing, IMHO. I have one more question on that. It seems that SQLite has this optimization working with ROLLBACK conflict action. We cannot doing so, because of some problem? Did this problem described / trackerized somewhere? Or something changes underhood and makes this impossible? Are we know exact reason or just observing it does not work? > +#ifdef SQLITE_TEST > +/* > + * The following global variable is incremented whenever the > + * transfer optimization is used. This is used for testing > + * purposes only - to make sure the transfer optimization really > + * is happening when it is supposed to. > + */ > +int sql_xfer_count = 0; > +#endif I think it would be good to mention the opcode where the counter is incremented. You can follow the style in which other counters are described (they are mostly mention opcodes). > -/* Opcode: RowData P1 P2 * * * > +/* Opcode: RowData P1 P2 * * P5 We can increase the counter on per-operation basis instead of per-row by adding the flag to OP_OpenWrite. It will save some CPU cycles :) > +#ifdef SQLITE_TEST > + if ((pOp->p5 & OPFLAG_XFER_OPT) != 0) { > + pOp->p5 = 0; > + sql_xfer_count++; > + } > +#endif 1. Not actual due to 2, but it would be better to use `pOp->p5 &= ~OPFLAG_XFER_OPT` to drop just that flag. 2. It is counter-intuitive, IMHO, to change operation flags during that operation. So, said above, vote to move it to OP_OpenWrite. > +local bfr, aftr > + What do you plan to do with saved letters? :) Really, such abbreviations just makes reading harder with no gains. > +local function do_xfer_test(test_number, return_code) > + test_name = string.format("xfer-optimization-1.%d", test_number) > + test:do_test( > + test_name, > + function() > + return {aftr - bfr} > + end, { > + -- <test_name> > + return_code > + -- <test_name> > + }) > +end That code can be written simpler (consider tap module documentation): test:is(after - before, exp, test_name) I suggest to create wrappers like so (I didn't test it): local function do_xfer_test(test_func, test, test_name, func, exp, opts) local opts = opts or {} local exp_xfer_count = opts.exp_xfer_count local before = box.sql.debug().sql_xfer_count local ok = test_func(test, test_name, func, exp) local after = box.sql.debug().sql_xfer_count if exp_xfer_count ~= nil then ok = ok and test:is(after - before, exp_xfer_count, test_name .. '_xfer_count') end return ok end test.do_execsql_xfer_test = function(test, test_name, func, exp, opts) return do_xfer_test(test.do_execsql_test, test, test_name, func, exp, opts) end test.do_catchsql_xfer_test = function(test, test_name, func, exp, opts) return do_xfer_test(test.do_catchsql_test, test, test_name, func, exp, opts) end And use it like so: test:do_catchsql_xfer_test( "xfer-optimization-1.1", [[ CREATE TABLE t1(a INTEGER PRIMARY KEY, b INTEGER UNIQUE); INSERT INTO t1 VALUES (1, 1), (2, 2), (3, 3); CREATE TABLE t2(a INTEGER PRIMARY KEY, b INTEGER UNIQUE); INSERT INTO t2 SELECT * FROM t1; ]], { -- <xfer-optimization-1.1> 0 -- <xfer-optimization-1.1> }), { exp_xfer_count = 1 } ) By the way, you can revive xfer cases in test/sql-tap/with2.test.lua. Or drop it if your new test includes all related cases from with2. On Fri, Jul 20, 2018 at 07:58:48PM +0300, Nikita Tatunov wrote: > Ooops. Thank you! fixed it and pushed. > > пт, 20 июл. 2018 г. в 19:43, n.pettik <[1]korablev@tarantool.org>: > > LGTM. > > diff --git a/src/box/sql/insert.c b/src/box/sql/insert.c > index 3c3bf37..4f52fa5 100644 > --- a/src/box/sql/insert.c > +++ b/src/box/sql/insert.c > @@ -1869,7 +1869,7 @@ xferOptimization(Parse * pParse, /* Parser > context */ > * table (tab1) is initially empty. > */ > > - /* The Vdbe we're building*/ > + /* The Vdbe struct we're building. */ > > You misunderstood me. What I mean is: > struct Vibe *v = …; > > Vdbe *v = sqlite3GetVdbe(pParse); > > References > > 1. mailto:korablev@tarantool.org
next prev parent reply other threads:[~2018-07-29 1:12 UTC|newest] Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-04-18 15:32 [tarantool-patches] " N.Tatunov 2018-04-18 16:33 ` [tarantool-patches] " Hollow111 2018-04-19 11:22 ` n.pettik 2018-04-19 15:36 ` Hollow111 2018-04-20 1:02 ` n.pettik 2018-04-20 15:09 ` Hollow111 2018-04-20 16:09 ` n.pettik 2018-04-20 17:59 ` Hollow111 2018-04-23 23:40 ` n.pettik 2018-04-27 15:45 ` Hollow111 2018-05-03 22:57 ` n.pettik 2018-05-04 12:54 ` Hollow111 2018-06-28 10:18 ` Alexander Turenko 2018-07-09 15:50 ` Alexander Turenko 2018-07-16 12:54 ` Nikita Tatunov 2018-07-16 13:06 ` n.pettik 2018-07-16 13:20 ` Nikita Tatunov 2018-07-16 18:37 ` Nikita Tatunov 2018-07-16 19:12 ` n.pettik 2018-07-16 21:27 ` Nikita Tatunov 2018-07-18 15:13 ` n.pettik 2018-07-18 20:18 ` Nikita Tatunov 2018-07-19 0:20 ` n.pettik 2018-07-19 17:26 ` Nikita Tatunov 2018-07-20 3:20 ` n.pettik 2018-07-20 11:56 ` Nikita Tatunov 2018-07-20 16:43 ` n.pettik 2018-07-20 16:58 ` Nikita Tatunov 2018-07-29 1:12 ` Alexander Turenko [this message] 2018-07-29 11:23 ` n.pettik 2018-07-29 15:16 ` Alexander Turenko 2018-07-30 18:33 ` Nikita Tatunov 2018-07-30 22:17 ` Alexander Turenko 2018-07-31 11:48 ` Nikita Tatunov 2018-07-31 13:29 ` Alexander Turenko 2018-07-31 17:04 ` Nikita Tatunov 2018-07-31 17:44 ` Alexander Turenko 2018-08-21 16:43 ` Kirill Yukhin
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20180729011251.eitp7cisv6jv5opj@tkn_work_nb \ --to=alexander.turenko@tarantool.org \ --cc=hollow653@gmail.com \ --cc=tarantool-patches@freelists.org \ --subject='[tarantool-patches] Re: [PATCH] sql: xfer optimization issue' \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: link
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox