…engine functions and we use it to see performance and scalability in this simple cases. We also use CPU… READ_PK_RANGE Query: SELECT min(dob) FROM $tableName WHERE id between %d and %d Access by range of PK …(dob) FROM $tableName The hardest query performs a scan of all million rows. InnoDB is better …
Post: PBXT benchmarks
April 8, 2007 By 14 Comments
…engine functions and we use it to see performance and scalability in this simple cases. We also use …PK. READ_PK_RANGE Query: SELECT min(dob) FROM $tableName WHERE id between %d and %d Access by range of PK …(dob) FROM $tableName The hardest query performs a scan of all million rows. General notes In …
Post: A case for MariaDB's Hash Joins
May 31, 2012 By Leave a Comment
… table by using values of the columns participating in the equijoin condition. The hash table is accessed by using a hash function on… to do an index range scan on the secondary key o_orderdate which results in random scans of the PK to fetch the columns that are not part of the secondary key. Even though MySQL 5.6 uses…
Post: Index Condition Pushdown in MySQL 5.6 and MariaDB 5.5 and its performance impact
March 12, 2012 By 12 Comments
… in cases such as range scans, where index parts after the part on which range condition is applied cannot be used for filtering records…
Post: Join Optimizations in MySQL 5.6 and MariaDB 5.5
April 4, 2012 By 4 Comments
…to one or more index range lookups. This means MySQL can… access the PK by arranging the secondary key values by PK …used in conjunction with BKA and that is MRR Key-ordered Scan. Let’s see what this optimization actually is. Key-ordered Scan… t2 are read and hash function is applied to the columns…
