1Z0-909 study guide
1Z0-909 · Work through your exam, one topic at a time.
The MySQL 8.0 Database Developer credential, exam code 1Z0-909, is an Oracle certification exam aimed at developers who build and maintain applications against MySQL 8.0 databases. It suits working developers, database engineers, and backend specialists who want a verifiable signal of practical MySQL 8.0 development skill rather than administration-only knowledge. The 1Z0-909 study guide has 10 sections and about 3,616 words.
01Data Types
The Data Types domain checks whether you can choose a column type whose range, precision, storage, and comparison behavior match the application. Questions often hinge on exact versus approximate numerics, temporal range and time-zone handling, and string types under MySQL 8.0's utf8mb4 default.
371 words, about 2 min02SQL Statements
This domain tests fluent use of MySQL 8.0 DDL and DML: creating and altering objects, inserting and modifying rows, joining tables, grouping, using subqueries and common table expressions, and applying window functions. Expect questions about affected-row counts, duplicate-key handling, and SQL mode effects.
390 words, about 2 min03SQL Functions
The SQL Functions domain checks your ability to use MySQL 8.0 built-in functions correctly in SELECT lists, WHERE clauses, and grouping. It covers string, numeric, date and time, control-flow, aggregate, and window functions, with emphasis on NULL propagation and return types.
348 words, about 2 min04Transactions and Locking
Transactions and Locking tests InnoDB's ACID behavior, isolation levels, explicit transaction control, locking reads, and deadlock handling. Questions often present two sessions and ask what each sees or whether a statement blocks.
377 words, about 2 min05Views and Temporary Tables
This domain checks how to define and use views and temporary tables, including algorithm selection, updatability, check options, and session scope. Expect questions about which view definitions can be merged, which are updatable, and when a temporary table hides a base table.
394 words, about 2 min06Stored Programs
Stored Programs covers procedures, functions, triggers, and events: creation syntax, parameter modes, local variables, cursors, handlers, and execution characteristics. Questions test delimiters, return values, trigger timing, and the event scheduler.
351 words, about 2 min07Prepared Statements
Prepared Statements tests server-side prepare, execute, and deallocate operations, placeholder rules, and the difference between SQL text and data. It also checks how prepared statements help prevent SQL injection and when dynamic SQL must be built differently.
338 words, about 2 min08JSON
The JSON domain tests the JSON data type, path expressions, modification functions, validation, and querying JSON with SQL. MySQL 8.0 adds JSON TABLE, JSON aggregation, and generated columns for indexing JSON values.
321 words, about 2 min09Character Sets and Collations
Character Sets and Collations tests how MySQL stores and compares strings. Questions cover utf8mb4, collation suffixes, connection character sets, introducers, and the effect of collation on comparisons and indexes.
362 words, about 2 min10Error Handling and Diagnostics
Error Handling and Diagnostics tests how stored programs and applications detect, handle, and report errors: condition handlers, SQLSTATE values, SIGNAL and RESIGNAL, GET DIAGNOSTICS, and warning inspection. HANDLER FOR condition value statement defines a handler.
364 words, about 2 min