WL#1563 - Modify MySQL to support fast CREATE/DROP INDEX

NDB cluster is not fully supported. This will be added with
WL 1892 (NDB Handler: Add support for CREATE/DROP INDEX).
Some preparatory code for this is already present though.
A change for the "duplicate key" error message is planned
for another changeset.


include/my_base.h:
  WL#1563 - Modify MySQL to support fast CREATE/DROP INDEX
  Defined a mask of flags which must be the same for two indexes
  if they should compare as compatible.
  Added an error number for a new drop index error message.
mysql-test/r/key.result:
  WL#1563 - Modify MySQL to support fast CREATE/DROP INDEX
  The test result.
mysql-test/t/key.test:
  WL#1563 - Modify MySQL to support fast CREATE/DROP INDEX
  The test case.
sql/handler.cc:
  WL#1563 - Modify MySQL to support fast CREATE/DROP INDEX
  Prepared for a later change in an error message:
  Replace index number by index name for "duplicate key" error.
  Added handling for the new drop index error message.
sql/handler.h:
  WL#1563 - Modify MySQL to support fast CREATE/DROP INDEX
  Added new flags and methods.
  Removed old flags and methods (from the last attempt).
sql/share/errmsg.txt:
  WL#1563 - Modify MySQL to support fast CREATE/DROP INDEX
  Added a new error message for drop index.
sql/sql_table.cc:
  WL#1563 - Modify MySQL to support fast CREATE/DROP INDEX
  Moved definitions to the top of the file.
  In mysql_prepare_table() allow an index to have the name
  "PRIMARY" if it has the key type "Key::PRIMARY".
  Added a parenthesis for readability.
  Removed old code from the last attempt.
  Some changes to compare_tables():
  - Input parameter "List<Key> *key_list" is replaced by
    "KEY *key_info_buffer, uint key_count".
  - Output parameters added: "index_drop_buffer/index_drop_count"
    and "index_add_buffer/index_add_count".
  - Key comparison must now find matching keys in changed
    old and new key lists.
  - Key comparison of a key is easier now because both old
    and new keys are of type 'KEY'.
  Call mysql_prepare_table() before compare_tables(). The
  translated KEY structs are needed at some places now.
  Inserted a code segment for checking alter_table_flags().
  Removed mysql_prepare_table() from the 'partition' branches
  (it is done above now).
  Removed a pair of unnecessary braces.
  Inserted a code segment for executing fast add/drop index.
  Made close of table dependent on whether it was opened.
  Prepared for NDB cluster support.
  Fixed commit to be called outside of LOCK_open.

include/my_base.h

@@ -206,6 +206,11 @@ enum ha_base_keytype {
 #define HA_NULL_ARE_EQUAL	2048	/* NULL in key are cmp as equal */
 #define HA_GENERATED_KEY	8192	/* Automaticly generated key */
 
+        /* The combination of the above can be used for key type comparison. */
+#define HA_KEYFLAG_MASK (HA_NOSAME | HA_PACK_KEY | HA_AUTO_KEY | \
+                         HA_BINARY_PACK_KEY | HA_FULLTEXT | HA_UNIQUE_CHECK | \
+                         HA_SPATIAL | HA_NULL_ARE_EQUAL | HA_GENERATED_KEY)
+
 	/* Automatic bits in key-flag */
 
 #define HA_SPACE_PACK_USED	 4	/* Test for if SPACE_PACK used */
@@ -349,8 +354,9 @@ enum ha_base_keytype {
 #define HA_ERR_NO_PARTITION_FOUND 160  /* There's no partition in table for
                                           given value */
 #define HA_ERR_RBR_LOGGING_FAILED 161  /* Row-based binlogging of row failed */
+#define HA_ERR_DROP_INDEX_FK      162  /* Index needed in foreign key constr. */
 
-#define HA_ERR_LAST               161  /* Copy last error no */
+#define HA_ERR_LAST               162  /* Copy last error no */
 
 /* Add error numbers before HA_ERR_LAST and change it accordingly. */
 #define HA_ERR_ERRORS            (HA_ERR_LAST - HA_ERR_FIRST + 1)

mysql-test/r/key.result

@@ -396,3 +396,71 @@ a	int(11)	NO	PRI
 b	varchar(20)	NO	MUL		
 c	varchar(20)	NO			
 drop table t1;
+create table t1 (
+c1 int,
+c2 char(12),
+c3 varchar(123),
+c4 timestamp,
+index (c1),
+index i1 (c1),
+index i2 (c2),
+index i3 (c3),
+unique i4 (c4),
+index i5 (c1, c2, c3, c4),
+primary key (c2, c3),
+index (c2, c4));
+show create table t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` int(11) default NULL,
+  `c2` char(12) NOT NULL default '',
+  `c3` varchar(123) NOT NULL default '',
+  `c4` timestamp NOT NULL default CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP,
+  PRIMARY KEY  (`c2`,`c3`),
+  UNIQUE KEY `i4` (`c4`),
+  KEY `c1` (`c1`),
+  KEY `i1` (`c1`),
+  KEY `i2` (`c2`),
+  KEY `i3` (`c3`),
+  KEY `i5` (`c1`,`c2`,`c3`,`c4`),
+  KEY `c2` (`c2`,`c4`)
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+alter table t1 drop index c1;
+alter table t1 add index (c1);
+alter table t1 add index (c1);
+alter table t1 drop index i3;
+alter table t1 add index i3 (c3);
+alter table t1 drop index i2, drop index i4;
+alter table t1 add index i2 (c2), add index i4 (c4);
+alter table t1 drop index i2, drop index i4, add index i6 (c2, c4);
+alter table t1 add index i2 (c2), add index i4 (c4), drop index i6;
+alter table t1 drop index i2, drop index i4, add unique i4 (c4);
+alter table t1 add index i2 (c2), drop index i4, add index i4 (c4);
+alter table t1 drop index c2, add index (c2(4),c3(7));
+alter table t1 drop index c2, add index (c2(4),c3(7));
+alter table t1 add primary key (c1, c2), drop primary key;
+alter table t1 drop primary key;
+alter table t1 add primary key (c1, c2), drop primary key;
+ERROR 42000: Can't DROP 'PRIMARY'; check that column/key exists
+show create table t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` int(11) NOT NULL default '0',
+  `c2` char(12) NOT NULL default '',
+  `c3` varchar(123) NOT NULL default '',
+  `c4` timestamp NOT NULL default CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP,
+  KEY `i1` (`c1`),
+  KEY `i5` (`c1`,`c2`,`c3`,`c4`),
+  KEY `c1` (`c1`),
+  KEY `c1_2` (`c1`),
+  KEY `i3` (`c3`),
+  KEY `i2` (`c2`),
+  KEY `i4` (`c4`),
+  KEY `c2` (`c2`(4),`c3`(7))
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+insert into t1 values(1, 'a', 'a', NULL);
+insert into t1 values(1, 'b', 'b', NULL);
+alter table t1 drop index i3, drop index i2, drop index i1;
+alter table t1 add index i3 (c3), add index i2 (c2), add unique index i1 (c1);
+ERROR 23000: Duplicate entry '1' for key 1
+drop table t1;

mysql-test/t/key.test

@@ -372,3 +372,61 @@ desc t1;
 drop table t1;
 
 # End of 4.1 tests
+
+#
+# WL#1563 - Modify MySQL to support on-line CREATE/DROP INDEX
+# To test if this really works, you need to run with --debug
+# and check the trace file.
+#
+# Create a table with named and unnamed indexes.
+create table t1 (
+    c1 int,
+    c2 char(12),
+    c3 varchar(123),
+    c4 timestamp,
+    index (c1),
+    index i1 (c1),
+    index i2 (c2),
+    index i3 (c3),
+    unique i4 (c4),
+    index i5 (c1, c2, c3, c4),
+    primary key (c2, c3),
+    index (c2, c4));
+show create table t1;
+# Some simple tests.
+alter table t1 drop index c1;
+alter table t1 add index (c1);
+# This creates index 'c1_2'.
+alter table t1 add index (c1);
+alter table t1 drop index i3;
+alter table t1 add index i3 (c3);
+# Two indexes at the same time.
+alter table t1 drop index i2, drop index i4;
+alter table t1 add index i2 (c2), add index i4 (c4);
+# Three indexes, one of them reversely.
+alter table t1 drop index i2, drop index i4, add index i6 (c2, c4);
+alter table t1 add index i2 (c2), add index i4 (c4), drop index i6;
+# include an unique index.
+alter table t1 drop index i2, drop index i4, add unique i4 (c4);
+alter table t1 add index i2 (c2), drop index i4, add index i4 (c4);
+# Modify an index by changing its definition.
+alter table t1 drop index c2, add index (c2(4),c3(7));
+# Change nothing. The new key definition is the same as the old one.
+alter table t1 drop index c2, add index (c2(4),c3(7));
+# Test primary key handling.
+alter table t1 add primary key (c1, c2), drop primary key;
+alter table t1 drop primary key;
+# Drop is checked first. Primary key must exist.
+--error 1091
+alter table t1 add primary key (c1, c2), drop primary key;
+show create table t1;
+# Insert non-unique values.
+insert into t1 values(1, 'a', 'a', NULL);
+insert into t1 values(1, 'b', 'b', NULL);
+# Drop some indexes for new adds.
+alter table t1 drop index i3, drop index i2, drop index i1;
+# Add indexes, one is unique on non-unique values.
+--error 1062
+alter table t1 add index i3 (c3), add index i2 (c2), add unique index i1 (c1);
+drop table t1;
+

sql/handler.cc

@@ -1851,7 +1851,12 @@ void handler::print_error(int error, myf errflag)
 	str.length(max_length-4);
 	str.append(STRING_WITH_LEN("..."));
       }
+#ifdef XXX_TO_BE_DONE_BY_A_FOLLOWUP_OF_WL1563
+      my_printf_error(ER_DUP_ENTRY, "Duplicate entry '%s' for key '%s'",
+                      MYF(0), str.c_ptr(), table->key_info[key_nr].name);
+#else
       my_error(ER_DUP_ENTRY, MYF(0), str.c_ptr(), key_nr+1);
+#endif
       DBUG_VOID_RETURN;
     }
     textno=ER_DUP_KEY;
@@ -1936,6 +1941,15 @@ void handler::print_error(int error, myf errflag)
   case HA_ERR_RBR_LOGGING_FAILED:
     textno= ER_BINLOG_ROW_LOGGING_FAILED;
     break;
+  case HA_ERR_DROP_INDEX_FK:
+  {
+    const char *ptr= "???";
+    uint key_nr= get_dup_key(error);
+    if ((int) key_nr >= 0)
+      ptr= table->key_info[key_nr].name;
+    my_error(ER_DROP_INDEX_FK, MYF(0), ptr);
+    DBUG_VOID_RETURN;
+  }
   default:
     {
       /* The error was "unknown" to this function.
@@ -1984,7 +1998,7 @@ uint handler::get_dup_key(int error)
   DBUG_ENTER("handler::get_dup_key");
   table->file->errkey  = (uint) -1;
   if (error == HA_ERR_FOUND_DUPP_KEY || error == HA_ERR_FOUND_DUPP_UNIQUE ||
-      error == HA_ERR_NULL_IN_SPATIAL)
+      error == HA_ERR_NULL_IN_SPATIAL || error == HA_ERR_DROP_INDEX_FK)
     info(HA_STATUS_ERRKEY | HA_STATUS_NO_LOCK);
   DBUG_RETURN(table->file->errkey);
 }

sql/handler.h

@@ -110,8 +110,29 @@
 #define HA_KEYREAD_ONLY         64	/* Support HA_EXTRA_KEYREAD */
 
 /* bits in alter_table_flags */
-#define HA_ONLINE_ADD_EMPTY_PARTITION 1
-#define HA_ONLINE_DROP_PARTITION 2
+#define HA_ONLINE_ADD_EMPTY_PARTITION           0x00000001
+#define HA_ONLINE_DROP_PARTITION                0x00000002
+/*
+  These bits are set if different kinds of indexes can be created
+  off-line without re-create of the table (but with a table lock).
+*/
+#define HA_ONLINE_ADD_INDEX_NO_WRITES           0x00000004 /*add index w/lock*/
+#define HA_ONLINE_DROP_INDEX_NO_WRITES          0x00000008 /*drop index w/lock*/
+#define HA_ONLINE_ADD_UNIQUE_INDEX_NO_WRITES    0x00000010 /*add unique w/lock*/
+#define HA_ONLINE_DROP_UNIQUE_INDEX_NO_WRITES   0x00000020 /*drop uniq. w/lock*/
+#define HA_ONLINE_ADD_PK_INDEX_NO_WRITES        0x00000040 /*add prim. w/lock*/
+#define HA_ONLINE_DROP_PK_INDEX_NO_WRITES       0x00000080 /*drop prim. w/lock*/
+/*
+  These are set if different kinds of indexes can be created on-line
+  (without a table lock). If a handler is capable of one or more of
+  these, it should also set the corresponding *_NO_WRITES bit(s).
+*/
+#define HA_ONLINE_ADD_INDEX                     0x00000100 /*add index online*/
+#define HA_ONLINE_DROP_INDEX                    0x00000200 /*drop index online*/
+#define HA_ONLINE_ADD_UNIQUE_INDEX              0x00000400 /*add unique online*/
+#define HA_ONLINE_DROP_UNIQUE_INDEX             0x00000800 /*drop uniq. online*/
+#define HA_ONLINE_ADD_PK_INDEX                  0x00001000 /*add prim. online*/
+#define HA_ONLINE_DROP_PK_INDEX                 0x00002000 /*drop prim. online*/
 
 /*
   Index scan will not return records in rowid order. Not guaranteed to be
@@ -134,16 +155,6 @@
 */
 #define MAX_HA 15
 
-/*
-  Bits in index_ddl_flags(KEY *wanted_index)
-  for what ddl you can do with index
-  If none is set, the wanted type of index is not supported
-  by the handler at all. See WorkLog 1563.
-*/
-#define HA_DDL_SUPPORT   1 /* Supported by handler */
-#define HA_DDL_WITH_LOCK 2 /* Can create/drop with locked table */
-#define HA_DDL_ONLINE    4 /* Can create/drop without lock */
-
 /*
   Parameters for open() (in register form->filestat)
   HA_GET_INFO does an implicit HA_ABORT_IF_LOCKED
@@ -1442,11 +1453,13 @@ class handler :public Sql_alloc
   virtual void set_part_info(partition_info *part_info) { return; }
 #endif
   virtual ulong index_flags(uint idx, uint part, bool all_parts) const =0;
-  virtual ulong index_ddl_flags(KEY *wanted_index) const
-  { return (HA_DDL_SUPPORT); }
+
   virtual int add_index(TABLE *table_arg, KEY *key_info, uint num_of_keys)
   { return (HA_ERR_WRONG_COMMAND); }
-  virtual int drop_index(TABLE *table_arg, uint *key_num, uint num_of_keys)
+  virtual int prepare_drop_index(TABLE *table_arg, uint *key_num,
+                                 uint num_of_keys)
+  { return (HA_ERR_WRONG_COMMAND); }
+  virtual int final_drop_index(TABLE *table_arg)
   { return (HA_ERR_WRONG_COMMAND); }
 
   uint max_record_length() const

sql/share/errmsg.txt

@@ -5779,3 +5779,6 @@ ER_EVENT_SAME_NAME
         eng "Same old and new event name"
 ER_EVENT_DATA_TOO_LONG
         eng "Data for column '%s' too long"
+ER_DROP_INDEX_FK
+        eng "Cannot drop index '%-.64s': needed in a foreign key constraint"
+        ger "Kann Index '%-.64s' nicht lschen: wird fr einen einen Fremdschlssel bentigt"