DefaultTempTableNameGenerator

better handling for temp table names - e.g. postgres has a 64-char table name limit, so we want to avoid running into that. This method generates a table name with (by default) at most 64 characters (4 * affixLength + 2 * affixSeparator.length + hashLength).

T+D destinations simply appended TMP_TABLE_SUFFIX to the table name, and should use TableName.asOldStyleTempTable instead

Not deprecated, but the interface it implements is deprecated.