From: Chris Sosnin <k.sosnin@tarantool.org> To: Nikita Pettik <korablev@tarantool.org>, Vladislav Shpilevoy <v.shpilevoy@tarantool.org> Cc: tarantool-patches@dev.tarantool.org Subject: Re: [Tarantool-patches] [PATCH 4/4] sql: provide a user friendly frontend for accessing session settings Date: Wed, 18 Mar 2020 13:00:56 +0300 [thread overview] Message-ID: <C538DF16-8377-456E-8987-4ADC3824F27E@tarantool.org> (raw) In-Reply-To: <20200317201232.GA4294@tarantool.org> [-- Attachment #1: Type: text/plain, Size: 5352 bytes --] > On 17 Mar 2020, at 23:12, Nikita Pettik <korablev@tarantool.org> wrote: > > On 17 Mar 20:26, Chris Sosnin wrote: >> >> >>> On 16 Mar 2020, at 20:02, Nikita Pettik <korablev@tarantool.org> wrote: >>> >>> On 17 Feb 15:12, Chris Sosnin wrote: >>>> Currently if a user wants to change session setting with sql, he has >>>> to execute non-obvious query, thus, we introduce a more native way to >>>> do this. >>> >>> It is not about non-obvious queries, but it is all about documentation: >>> the better feature is described, the clearer its usage turns out to be >>> for user. >> >> Should I change the commit message? I though this patchset is about simplifying >> the way session settings are updated? > > I would say: > > Currently if a user wants to change session settings via SQL, one has > to execute UPDATE query like: > [[UPDATE "_session_settings" SET "value" = true WHERE "name" = 'name']] > However, direct access to system spaces isn't considered to be good practice. > To avoid that and a bit simplify user's life, we introduce SQL shortcut command > SET with following syntax: SET <setting_name> = <value>. <setting_name> is > supposed to be name of setting (note that it is uppercased as any other > non-quoted indentifiers in SQL) and <value> - value of corresponding setting to > be set; <value> should be either literal or binding marker. Also it is worth > noting that SET doesn't provide any implicit casts, so <value> must be of the > type corresponding to the setting being updated. > > Example: > ... > > ^ It is up to you. I took the beginning as long as the rest is described in the doc request (except for implicit casts note, thanks for pointing that out, fixed): Currently if a user wants to change session setting with SQL, one has to execute UPDATE query like: [[UPDATE "_session_settings" SET "value" = true WHERE "name" = 'name']] However, direct access to system spaces isn't considered to be a good practice. To avoid that and a bit simplify user's life, we introduce SQL shortcut command SETTING SET. > >>> >>>> Closes #4711 >>>> >>>> @TarantoolBot document >>>> Title: API for accessing _session_settings space. >>>> There are two ways of updating values of session settings: >>>> via Lua and SQL. >>>> >>>> SQL: >>>> Instead of typing long UPDATE query one can use the SET statement: >>>> `box.execute([[SET "<setting_name>" = <new_value>]])`. >>>> Note, that this query is case sensitive so the name must be quoted. >>>> >>>> Example: >>>> ``` >>>> tarantool> box.execute([[set "sql_default_engine" = 'memtx']]) >>>> --- >>>> - row_count: 1 >>>> ... >>>> >>>> tarantool> box.execute([[set "sql_defer_foreign_keys" = true]]) >>> >>> Why didn't you consider show/get command to retrieve setting value? >>> Otherwise, you simplify way to set session local options, but doesn't >>> provide the same way to extract current values. >> >> SELECT * FROM “_session_settings” is simple enough, isn’t it? > > In this case you'll get list of all settings. To get specific one > we should use this query: > > SELECT value FROM "_session_settings" WHERE "name" = 'xxx' > > I do not insist on implementing GET/SHOW SQL syntax now tho. > >>>> diff --git a/src/box/sql/sqlInt.h b/src/box/sql/sqlInt.h >>>> index d1fcf4761..3ffae5970 100644 >>>> --- a/src/box/sql/sqlInt.h >>>> +++ b/src/box/sql/sqlInt.h >>>> @@ -4510,4 +4510,15 @@ int >>>> sql_fieldno_by_name(struct Parse *parse_context, struct Expr *field_name, >>>> uint32_t *fieldno); >>>> >>>> diff --git a/src/box/sql/vdbe.c b/src/box/sql/vdbe.c >>>> index 620d74e66..c81486fa6 100644 >>>> --- a/src/box/sql/vdbe.c >>>> +++ b/src/box/sql/vdbe.c >>>> @@ -55,6 +55,7 @@ >>>> #include "box/schema.h" >>>> #include "box/space.h" >>>> #include "box/sequence.h" >>>> +#include "box/session_settings.h" >>>> >>>> /* >>>> * Invoke this macro on memory cells just prior to changing the >>>> @@ -5248,6 +5249,55 @@ case OP_IncMaxid: { >>>> break; >>>> } >>>> >>>> +/* Opcode: Set P1 P2 * * * >>>> + * >>>> + * Set the new value of the session setting. P1 is the id of the >>>> + * setting in the session_settings array, P2 is the register >>>> + * holding a value. >>>> + */ >>>> +case OP_Set: { >>> >>> Please, use more specific opcode name. Like OP_SettingSet. >> >> Didn’t we accept ’set’ syntax? > > SET is okay, but I don't mind SET SETTING as well. OP_Set is too general > name - SET keyword is also part of UPDATE syntax, so it may confuse other > developers. Except for this nit patch LGTM. Here are the fixes: - sqlVdbeAddOp2(vdbe, OP_Set, index, target); + sqlVdbeAddOp2(vdbe, OP_SetSetting, index, target); -///////////////////////////// The SET command //////////////////////////////// -cmd ::= SET nm(X) EQ expr(Y). { +///////////////////////////// The SETTING SET command //////////////////////// +cmd ::= SETTING SET nm(X) EQ expr(Y). { -/* Opcode: Set P1 P2 * * * +/* Opcode: SetSetting P1 P2 * * * -case OP_Set: { +case OP_SetSetting: { And of course I had to change the grammar and tests. Changes are on the branch with the second version of Lua patch: https://github.com/tarantool/tarantool/tree/ksosnin/gh-4712-session-settings-v2 [-- Attachment #2: Type: text/html, Size: 28033 bytes --]
next prev parent reply other threads:[~2020-03-18 10:00 UTC|newest] Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-02-17 12:12 [Tarantool-patches] [PATCH 0/4] box: session settings fixes Chris Sosnin 2020-02-17 12:12 ` [Tarantool-patches] [PATCH 1/4] box: replace session_settings modules with a single array Chris Sosnin 2020-02-17 12:12 ` [Tarantool-patches] [PATCH 2/4] box: add binary search for _session_settings space Chris Sosnin 2020-03-16 14:16 ` Nikita Pettik 2020-03-16 22:53 ` Vladislav Shpilevoy 2020-03-17 17:24 ` Nikita Pettik 2020-02-17 12:12 ` [Tarantool-patches] [PATCH 3/4] box: provide a user friendly frontend for accessing session settings Chris Sosnin 2020-03-16 16:08 ` Nikita Pettik 2020-03-16 22:53 ` Vladislav Shpilevoy 2020-03-17 14:27 ` Nikita Pettik 2020-03-17 14:36 ` Chris Sosnin 2020-02-17 12:12 ` [Tarantool-patches] [PATCH 4/4] sql: " Chris Sosnin 2020-03-16 17:02 ` Nikita Pettik 2020-03-16 22:53 ` Vladislav Shpilevoy 2020-03-17 17:26 ` Chris Sosnin 2020-03-17 20:12 ` Nikita Pettik 2020-03-17 21:00 ` Chris Sosnin 2020-03-18 10:00 ` Chris Sosnin [this message] -- strict thread matches above, loose matches on Subject: below -- 2020-03-30 9:13 [Tarantool-patches] [PATCH 0/4] session settings fixes Chris Sosnin 2020-03-30 9:13 ` [Tarantool-patches] [PATCH 4/4] sql: provide a user friendly frontend for accessing session settings Chris Sosnin 2020-04-03 15:19 ` Nikita Pettik 2020-04-04 21:56 ` Vladislav Shpilevoy 2020-04-10 15:40 ` Chris Sosnin 2020-04-11 17:18 ` Vladislav Shpilevoy 2020-04-13 7:50 ` Timur Safin 2020-02-03 22:17 [Tarantool-patches] [PATCH] " Vladislav Shpilevoy 2020-02-04 19:32 ` [Tarantool-patches] [PATCH 4/4] " Chris Sosnin 2020-02-06 22:16 ` Vladislav Shpilevoy 2020-02-07 9:40 ` Chris Sosnin 2020-02-10 22:09 ` Vladislav Shpilevoy 2020-02-17 11:46 ` Chris Sosnin 2020-02-17 11:56 ` Nikita Pettik
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