Developers’ mDay 2021: Bogdan Kecman, Oracle – MySQL nekad i sad
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The document summarizes the evolution of MySQL from its first release in 1995 to version 8.0 released in 2018. It highlights key features and functionality added over time, including improved performance, Unicode support, spatial data types, window functions, common table expressions, and high availability solutions. The document also briefly mentions Oracle's HeatWave and ColumnStore technologies for handling OLAP/OLTP workloads on MySQL.
Developers’ mDay 2021: Bogdan Kecman, Oracle – MySQL nekad i sad
- 1. MySQL – Nekad i Sad Bogdan Kecman CEO @BAD-TEAM MySQL Principal Technical Engineer @ORACLE #mDevDay, #mDevDay2021, Novi Sad, Jul 2021
- 2. Safe Harbor Statement The following is intended to outline our general product direction. It is intended for information purposes only, and may not be incorporated into any contract. It is not a commitment to deliver any material, code, or functionality, and should not be relied upon in making purchasing decisions. The development, release, and timing of any features or functionality described for Oracle’s products remains at the sole discretion of Oracle. 2
- 3. MySQL ● first release May 1995, TCX.SE ● ISAM ● Monty Widenius, David Axmark, Allan Larsson ● mSQL by Hyghes Technologies, Postgres (QUEL) ● SiGraf, Silicon Graphics Yugoslavia, SGI, IRIX, Vexy… ● Free but not open source => Dual Licence We need free SQL server 3
- 4. MySQL 3.20 – year 1996/97 / 3.19-3.23 – year 2000 ● 1995/1996, SiGraf, Silicon Graphics Yugoslavia, SGI, IRIX… ● ACID ● JOINS ● UNIONS ● RTREE, BTREE, SUBQUERY, TRIGGER, VIEW, XA transactions ● PREPARED STATEMENTS, PROCEDURES, CURSORS Only idiots need OUTER JOIN 4
- 6. MySQL 8.0 - 2018 ● Evolved beyond SQL-92 ● Evolved beyond relational dogma ● Supports window functions (over) ● Supports CommonTableExpressions (with) ● Transactional DDL (no more FRM files) ● Hash Joins, SKIP LOCKED, NO WAIT, Explain Analyze... One Giant Leap for SQL 6
- 7. MySQL 8.0 ● Support for the latest Unicode 9.0 ● UTF8MB4 is new default (utf8mb4_0900_ai_ci is default coll.) ● Accent and case sensitive collations (20+ lang specific) ● Improved performance (no, really, it’s unbelievably fast now) UTF8 7
- 8. MySQL 8.0 ● Geography Support (lat/lon) ● Spatial Reference Systems (SRS) Support ● SRID aware spatial datatypes, indexes and functions ● Informational Schema views about spatial data (ST_GEOMETRY_COLUMNS) ● GeoHash(), GeoJSON() GIS: SRS, SRID, IS Views, GeoHash and GeoJSON 8
- 9. MySQL 8.0 Common problem: hot row contention, multiple worker threads accessing the same rows ● Solution 1: start transaction; select * from seats where seat_no between 2 and 3 and booked = ‘no’ for update SKIP LOCKED; ● Solution 2: start transaction; select * from seats where seat_no between 2 and 3 and booked = ‘no’ for update NOWAIT; SKIP LOCKED and NOWAIT 9
- 10. MySQL 8.0 ● A derived table is a subquery in the FROM clause – SELECT … FROM (subquery) AS derived, t1 ● Common Table Expression is just like a derived table, but its declaration is put before the query block instead of in FROM clause – WITH derived AS ( subquery) SELECT … FROM derived, t1 ● It’s an alternative to derived table for readability, multiple references, increased performance ● Can be recursive (traverse hierarchies) CTEs (SQL:99) 10
- 11. MySQL 8.0 ● Similar to an aggregation function, performs a calculation across a set of rows that are related to the current row ● Window functions can access values of other rows “in the vicinity” of the current row Example (sum up total salary for each department): SELECT name, dept _id, salary, SUM(salary) OVER (PARTITION BY dept_id) AS dept_total FROM employee ORDER BY dept _id, name WINDOW functions (SQL: 2003) 11
- 12. MySQL 8.0 ● Illegal in SQL92 because a derived table cannot depend on other tables in the same FROM clause (it has to be constant over the query's duration ● A derived table cannot normally refer to (depend on) columns of preceding tables in the same FROM clause SELECT salesperson.name, max_sale.amount, max_sale.customer_name FROM salesperson, --find max size and customer at same time LATERAL (SELECT amount, customer_name FROM all_sales WHERE all_sales.salesperson_id = salesperson.id ORDER BY amount DESC LIMIT 1) AS max_sale; LATERAL derived tables (SQL:99) 12
- 13. MySQL HA ● Self managed groups of MySQL servers with multi master support – built in Group Replication plugin → InnoDB Cluster (Oracle) – Galera Cluster (Percona) ● MySQL Proxy, MySQL Router, MySQL Shell (Oracle) ● ProxySQL (Rene Cannao) ● Oracle Cloud MySQL Database Service (Oracle) ● MySQL MCCGE ndbcluster (Oracle) ● AWS RDS MySQL (Amazon) ● ... 13
- 15. HVALA!