Bug#26231 - select count(*) on myisam table returns wrong value
when index is used When the table contained TEXT columns with empty contents ('', zero length, but not NULL) _and_ strings starting with control characters like tabulator or newline, the empty values were not found in a "records in range" estimate. Hence count(*) missed these records. The reason was a different set of search flags used for key insert and key range estimation. I decided to fix the set of flags used in range estimation. Otherwise millions of databases around the world would require a repair after an upgrade. The consequence is that the manual must be fixed, which claims that TEXT columns are compared with "end space padding". This is true for CHAR/VARCHAR but wrong for TEXT. See also bug 21335.
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