[tarantool-patches] Re: [PATCH v11] sql: add index_def to struct Index

["n.pettik" <korablev@tarantool.org>]

Please, follow our SOP convention: if you send next patch version,
then resend it as a separate patch (git format-patch -1 --subject-prefix='PATCH v2’), 
and add changelog. If you simply want to send diff, then add it to each pace of
provided changes. In your case, it is better to send only diff AFTER changes
(not the whole patch), it makes review process MUCH easier.

>> Then:
>> 
>> CREATE TABLE t11 (s1 INT, a, constraint c1 UNIQUE(s1) on conflict replace, PRIMARY KEY(s1));
>> 
>> In this case creation of unique constraint c1 is omitted, but no errors or warnings are shown.
>> It is not a problem now, but when ALTER TABLE DROP CONSTRAINT is implemented,
>> it will be possible to drop c1 constraint. Eventually, user would be disappointed if tried to drop
>> this constraint but got an error.
> It seems to be out of the scope of the patch. Appropriate ticket:
> https://github.com/tarantool/tarantool/issues/3498

I don’t understand how that ticket is related to given issue. Again, problem lies in
silent absorption of unique constraint by primary index.

>> 
>>> +struct Index *
>>> +sql_index_alloc(struct sqlite3 *db, uint32_t part_count)
>>> {
>>> -	Index *p;		/* Allocated index object */
>>> -	int nByte;		/* Bytes of space for Index object + arrays */
>>> -
>>> -	nByte = ROUND8(sizeof(Index)) +		    /* Index structure   */
>>> -	    ROUND8(sizeof(struct coll *) * nCol) +  /* Index.coll_array  */
>>> -	    ROUND8(sizeof(uint32_t) * nCol) +       /* Index.coll_id_array*/
>>> -	    ROUND8(sizeof(LogEst) * (nCol + 1) +    /* Index.aiRowLogEst */
>>> -		   sizeof(i16) * nCol +		    /* Index.aiColumn    */
>>> -		   sizeof(enum sort_order) * nCol); /* Index.sort_order  */
>>> -	p = sqlite3DbMallocZero(db, nByte + nExtra);
>>> -	if (p) {
>>> -		char *pExtra = ((char *)p) + ROUND8(sizeof(Index));
>>> -		p->coll_array = (struct coll **)pExtra;
>>> -		pExtra += ROUND8(sizeof(struct coll **) * nCol);
>>> -		p->coll_id_array = (uint32_t *) pExtra;
>>> -		pExtra += ROUND8(sizeof(uint32_t) * nCol);
>>> -		p->aiRowLogEst = (LogEst *) pExtra;
>>> -		pExtra += sizeof(LogEst) * (nCol + 1);
>>> -		p->aiColumn = (i16 *) pExtra;
>>> -		pExtra += sizeof(i16) * nCol;
>>> -		p->sort_order = (enum sort_order *) pExtra;
>>> -		p->nColumn = nCol;
>>> -		*ppExtra = ((char *)p) + nByte;
>>> -	}
>>> +	/* Size of struct Index and aiRowLogEst. */
>>> +	int nByte = ROUND8(sizeof(struct Index)) +
>>> +		    ROUND8(sizeof(LogEst) * (part_count + 1));
>> Do we really need this alignment?
> No. Removed.

No, you don’t. Apply this diff:

diff --git a/src/box/sql/build.c b/src/box/sql/build.c
index d66777f73..d2fed97eb 100644
--- a/src/box/sql/build.c
+++ b/src/box/sql/build.c
@@ -2430,13 +2430,14 @@ sqlite3RefillIndex(Parse * pParse, Index * pIndex, int memRootPage)
 }
 
 struct Index *
-sql_index_alloc(struct sqlite3 *db)
+sql_index_alloc(struct sqlite3 *db, uint32_t part_count)
 {
        /* Size of struct Index and aiRowLogEst. */
-       int index_size = ROUND8(sizeof(struct Index));
+       int index_size = sizeof(struct Index) +
+                        sizeof(LogEst) * (part_count + 1);
        struct Index *p = sqlite3DbMallocZero(db, index_size);
        if (p != NULL)
-               p->aiRowLogEst = (LogEst *) ((char *)p + ROUND8(sizeof(*p)));
+               p->aiRowLogEst = (LogEst *) ((char *)p + sizeof(*p));
        return p;
 }

@@ -2769,11 +2757,10 @@ sql_create_index(struct Parse *parse, struct Token *token,
        if (sqlite3CheckIdentifierName(parse, name) != SQLITE_OK)
                goto exit_create_index;
 
-       index = sql_index_alloc(db);
+       index = sql_index_alloc(db, col_list->nExpr);

@@ -2769,11 +2757,10 @@ sql_create_index(struct Parse *parse, struct Token *token,
        if (sqlite3CheckIdentifierName(parse, name) != SQLITE_OK)
                goto exit_create_index;
 
-       index = sql_index_alloc(db);
+       index = sql_index_alloc(db, col_list->nExpr);
        if (index == NULL)
                goto exit_create_index;
 
-       assert(EIGHT_BYTE_ALIGNMENT(index->aiRowLogEst));

diff --git a/src/box/sql/sqliteInt.h b/src/box/sql/sqliteInt.h
index ae31dfae5..2082d6ca9 100644
--- a/src/box/sql/sqliteInt.h
+++ b/src/box/sql/sqliteInt.h
@@ -3631,7 +3631,7 @@ void sqlite3SrcListDelete(sqlite3 *, SrcList *);
  * @retval not NULL Index object.
  */
 struct Index *
-sql_index_alloc(struct sqlite3 *db);
+sql_index_alloc(struct sqlite3 *db, uint32_t part_count);

> Ok, removed detailed description, left a short one.

@@ -2538,19 +2539,15 @@ addIndexToTable(Index * pIndex, Table * pTab)
  * @param expr_list List of expressions, describe which columns
  *                  of 'table' are used in index and also their
  *                  collations, orders, etc.
- * @param idx_type Index type, one of the following:
- *                 SQLITE_IDXTYPE_APPDEF     0
- *                 SQLITE_IDXTYPE_UNIQUE     1
- *                 SQLITE_IDXTYPE_PRIMARYKEY 2.
+ * @param idx_type Index type: UNIQUE constraint, PK constraint,
+ *                 or created by <CREATE INDEX ...> stmt.

>> 
>>> @@ -2731,42 +2765,38 @@ sql_create_index(struct Parse *parse, struct Token *token,
>>> 	 * primary key or UNIQUE constraint.  We have to invent
>>> 	 * our own name.
>>> 	 */
>>> -	if (token) {
>>> -		zName = sqlite3NameFromToken(db, token);
>>> -		if (zName == 0)
>>> +	if (token != NULL) {
>>> +		name = sqlite3NameFromToken(db, token);
>>> +		if (name == NULL)
>>> 			goto exit_create_index;
>>> -		assert(token->z != 0);
>>> +		assert(token->z != NULL);
>>> 		if (!db->init.busy) {
>>> -			if (sqlite3HashFind(&db->pSchema->tblHash, zName) !=
>>> +			if (sqlite3HashFind(&db->pSchema->tblHash, name) !=
>>> 			    NULL) {
>>> -				sqlite3ErrorMsg(parse,
>>> -						"there is already a table named %s",
>>> -						zName);
>>> +				sqlite3ErrorMsg(parse, "there is already a "\
>>> +						"table named %s", name);
>>> 				goto exit_create_index;
>>> 			}
>>> 		}

You forgot about my comment:

>There is no need to prohibit creating index with table name, since
>index name is local for given table. And most of other DBs also
>allow to create index with table name.

Apply diff:

@@ -2705,14 +2702,6 @@ sql_create_index(struct Parse *parse, struct Token *token,
                if (name == NULL)
                        goto exit_create_index;
                assert(token->z != NULL);
-               if (!db->init.busy) {
-                       if (sqlite3HashFind(&db->pSchema->tblHash, name) !=
-                           NULL) {
-                               sqlite3ErrorMsg(parse, "there is already a "\
-                                               "table named %s", name);
-                               goto exit_create_index;
-                       }
-               }

>>> +
>>> +	bool is_unique = on_error != ON_CONFLICT_ACTION_NONE;
>> It seems to be so messy defining uniqueness by ON_CONFLICT_ACTION.
>> Lets refactor it somehow.
> Not sure about this. It seems that information about uniqueness is
> only in on_error parameter.

What? Lets then change signature and from parser pass additional parameter
which would tell if index is unique or not.

>>> diff --git a/src/box/sql/where.c b/src/box/sql/where.c
>>> index 85143ed20..7ca02095f 100644
>>> --- a/src/box/sql/where.c
>>> +++ b/src/box/sql/where.c
>>> @@ -372,13 +372,19 @@ whereScanInit(WhereScan * pScan,	/* The WhereScan object being initialized */
>>> 	pScan->is_column_seen = false;
>>> 	if (pIdx) {
>>> 		int j = iColumn;
>>> -		iColumn = pIdx->aiColumn[j];
>>> +		iColumn = pIdx->def->key_def->parts[j].fieldno;
>>> +		/*
>>> +		 * pIdx->tnum == 0 means that pIdx is a fake
>>> +		 * integer primary key index.
>>> +		 */
>>> +		if (pIdx->tnum == 0)
>>> +			iColumn = -1;
>> We are going to remove tnum from struct Index and struct Table.
>> So, if it is possible, use index->def->iid instead (or smth else).
> Removed with ‘fake_autoindex'

Well, if smb called index ‘fake_autoindex’, I guess strange things would happen.
Could we use for instance def->space_id == 0 as a sign of ‘fake_index'?.

> src/box/errcode.h                                  |   1 +
> src/box/sql.c                                      |  54 +-
> src/box/sql/analyze.c                              |  85 +--
> src/box/sql/build.c                                | 816 ++++++++++-----------
> src/box/sql/delete.c                               |  10 +-
> src/box/sql/expr.c                                 |  61 +-
> src/box/sql/fkey.c                                 | 216 +++---
> src/box/sql/insert.c                               | 145 ++--
> src/box/sql/pragma.c                               |  30 +-
> src/box/sql/select.c                               |   2 +-
> src/box/sql/sqliteInt.h                            | 116 +--
> src/box/sql/update.c                               |  39 +-
> src/box/sql/vdbeaux.c                              |   2 +-
> src/box/sql/vdbemem.c                              |  21 +-
> src/box/sql/where.c                                | 192 ++---
> src/box/sql/wherecode.c                            | 102 +--
> test/box/misc.result                               |   1 +
> test/sql-tap/analyze6.test.lua                     |   6 +-
> .../{collation.test.lua => collation1.test.lua}    |   7 +-
> test/sql-tap/colname.test.lua                      |   4 +-
> test/sql-tap/gh-2931-savepoints.test.lua           |   2 +-
> test/sql-tap/gh2140-trans.test.lua                 |   2 +-
> test/sql-tap/gh2259-in-stmt-trans.test.lua         |   8 +-
> test/sql-tap/gh2964-abort.test.lua                 |   2 +-
> test/sql-tap/identifier-characters.test.lua        |   2 +-
> test/sql-tap/identifier_case.test.lua              |   4 +-
> test/sql-tap/index1.test.lua                       |  14 +-
> test/sql-tap/index7.test.lua                       |  21 +-
> test/sql-tap/intpkey.test.lua                      |   4 +-
> test/sql-tap/misc1.test.lua                        |   2 +-
> test/sql-tap/unique.test.lua                       |   8 +-
> test/sql-tap/update.test.lua                       |   6 +-
> test/sql/insert-unique.result                      |   3 +-
> test/sql/iproto.result                             |   2 +-
> test/sql/message-func-indexes.result               |   8 +-
> test/sql/on-conflict.result                        |   2 +-
> test/sql/persistency.result                        |   6 +-
> test/sql/transition.result                         |   6 +-
> 38 files changed, 965 insertions(+), 1047 deletions(-)
> rename test/sql-tap/{collation.test.lua => collation1.test.lua} (97%)

Why have you renamed this test?

> +	if (is_system_space && idx_type == SQLITE_IDXTYPE_APPDEF) {
> +		diag_set(ClientError, ER_MODIFY_INDEX, name,
> +			 table->def->name, "creating indexes on system "
> +					   "spaces are prohibited”);

+               diag_set(ClientError, ER_MODIFY_INDEX, name, table->def->name,
+                        "can't create index on system space");

> +	char *sql_stmt = "";
> +	if (!db->init.busy && tbl_name != NULL) {
> +		int n = (int) (parse->sLastToken.z - token->z) +
> +			parse->sLastToken.n;
> +		if (token->z[n - 1] == ';')
> +			n--;
> +		sql_stmt = sqlite3MPrintf(db, "CREATE%s INDEX %.*s",
> +				       on_error == ON_CONFLICT_ACTION_NONE ?
> +				       "" : " UNIQUE", n, token->z);

Wrong alignment:

@@ -2809,8 +2796,8 @@ sql_create_index(struct Parse *parse, struct Token *token,
                if (token->z[n - 1] == ';')
                        n--;
                sql_stmt = sqlite3MPrintf(db, "CREATE%s INDEX %.*s",
-                                      on_error == ON_CONFLICT_ACTION_NONE ?
-                                      "" : " UNIQUE", n, token->z);
+                                         on_error == ON_CONFLICT_ACTION_NONE ?
+                                         "" : " UNIQUE", n, token->z);


Moreover, sql_stmt is obtained from sqlite3Malloc() and assigned to index->opts,
which in turn is released by common free().

> diff --git a/test/sql-tap/index7.test.lua b/test/sql-tap/index7.test.lua
> index 336f42796..4bd01b8b3 100755
> --- a/test/sql-tap/index7.test.lua
> +++ b/test/sql-tap/index7.test.lua
> @@ -1,6 +1,6 @@
> #!/usr/bin/env tarantool
> test = require("sqltester")
> -test:plan(5)
> +test:plan(7)
>  --!./tcltestrunner.lua
> -- 2013-11-04
> @@ -48,7 +48,7 @@ end
> -- do_test index7-1.1a {
> --   capture_pragma db out {PRAGMA index_list(t1)}
> --   db eval {SELECT "name", "partial", '|' FROM out ORDER BY "name"}
> --- } {sqlite_autoindex_t1_1 0 | t1a 1 | t1b 1 |}
> +-- } {sql_autoindex_t1_1 0 | t1a 1 | t1b 1 |}
> -- # Make sure the count(*) optimization works correctly with
> -- # partial indices.  Ticket [a5c8ed66cae16243be6] 2013-10-03.
> -- #
> @@ -303,4 +303,21 @@ test:do_catchsql_test(
>         1, "keyword \"WHERE\" is reserved"
>     })
> +test:do_catchsql_test(
> +        "index7-6.6",
> +        'CREATE TABLE test2 (a int, b int, c int, PRIMARY KEY (a, a, a, b, b, a, c))',
> +        nil)

Why nil? What does this test check at all?

> +
> +test:do_catchsql_test(
> +        "index7-6.7",
> +        [[
> +            CREATE TABLE test4(a,b,c,d, PRIMARY KEY(a,a,a,b,c));
> +            CREATE INDEX index1 on test4(b,c,a,c);
> +            SELECT "_index"."name" FROM "_index" JOIN "_space" WHERE
> +            "_index"."id" = "_space"."id" AND
> +            "_space"."name"='TEST4' AND
> +            "_index"."name"='INDEX1’;

Use indentation for nested select clause to make it more readable.
Moreover, add comment to the test which would explain what exactly this test checks.