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Bug#8841 - CHECKSUM TABLE is broken in MyISAM

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There are (at least) two implementations of the checksum
computation. One is in MyISAM for the quick checksum. It
is executed on every row change. The other is in the
SQL layer for the extended checksum. It retrieves all rows
of a table via the respective storage engine.

In former MySQL versions varchars were stored with their 
maximum length, but now with their real length similar to
blobs.

This change had been forgotten to take care of in the
extended checksum calculation. Hence too much data was
checksumed. In MyISAM this change had been taken care of 
already. Only the real data is included in the checksum.

I changed mysql_checksum_table() so that it uses the
length information of true varchar fields instead
of the field length like in former varchar 
implementations.
This commit is contained in:
ingo@mysql.com
2006-02-01 16:46:44 +01:00
parent edca1d6f07
commit c5a7bffcee
3 changed files with 10 additions and 9 deletions
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3
sql/sql_table.cc
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@ -4218,7 +4218,8 @@ bool mysql_checksum_table(THD *thd, TABLE_LIST *tables, HA_CHECK_OPT *check_opt)
for (uint i= 0; i < t->s->fields; i++ )
{
Field *f= t->field[i];
if (f->type() == FIELD_TYPE_BLOB)
if ((f->type() == FIELD_TYPE_BLOB) ||
(f->type() == MYSQL_TYPE_VARCHAR))
{
String tmp;
f->val_str(&tmp);