PostgreSQL
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4. SQL Syntax
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5. Data Definition
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6. Data Manipulation
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7. Queries
- 7.1. Overview | parser | analyser | rewriter | planner | executor
- 7.2. Table Expressions
- 7.3. Select Lists
- 7.4. Combining Queries
- 7.5. Sorting Rows
- 7.6. LIMIT and OFFSET
- 7.7. VALUES Lists
- 7.8. WITH Queries (Common Table Expressions)
- 7.9. Joins ｜ cross join 无on| inner join 有 on | left join left为主｜ right join为主
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8. Data Types
- 8.1. Numeric Types | int2,int4,int8 | real,double precision | smallserial, serial, bigserial
- 8.2. Monetary Types
- 8.3. Character Types | varchar | char | text
- 8.4. Binary Data Types
- 8.5. Date/Time Types
- 8.6. Boolean Type | true | yes | on | 1
- 8.7. Enumerated Types | order | type safety
- 8.8. Geometric Types | point | lines | boxes | polygons | circle
- 8.9. Network Address Types
- 8.10. Bit String Types todo
- 8.11. Text Search Types todo
- 8.12. UUID Type
- 8.13. XML Type todo
- 8.14. JSON Types | input output syntax | reparse
- 8.14. JSONB Types | binary | gin indexing
- 8.15. Arrays | input output syntax | accessing | modify | search
- 8.16. Composite Types
- 8.17. Range Types | input output syntax | GiST and SP-GiST index
- 8.18. Domain Types todo
- 8.19. Object Identifier Types todo
- 8.20. pg_lsn Type todo
- 8.21. Pseudo-Types todo
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9. Functions and Operators
- 9.1. Logical Operators
- 9.2. Comparison Functions and Operators
- 9.3. Mathematical Functions and Operators
- 9.4. String Functions and Operators
- 9.5. Binary String Functions and Operators
- 9.6. Bit String Functions and Operators
- 9.7. Pattern Matching
- 9.8. Data Type Formatting Functions
- 9.9. Date/Time Functions and Operators
- 9.10. Enum Support Functions
- 9.11. Geometric Functions and Operators
- 9.12. Network Address Functions and Operators
- 9.13. Text Search Functions and Operators
- 9.14. XML Functions
- 9.15. JSON Functions and Operators
- 9.16. Sequence Manipulation Functions
- 9.17. Conditional Expressions
- 9.18. Array Functions and Operators
- 9.19. Range Functions and Operators
- 9.20. Aggregate Functions
- 9.21. Window Functions
- 9.22. Subquery Expressions
- 9.23. Row and Array Comparisons
- 9.24. Set Returning Functions
- 9.25. System Information Functions and Operators
- 9.26. System Administration Functions
- 9.27. Trigger Functions
- 9.28. Event Trigger Functions
- 9.29. Statistics Information Functions
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10. Type Conversion
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11. Indexes
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11.9. Index-Only Scans and Covering Indexes
- Index only scan, 最优， select， where , order 都命中index
- Index scan, 第二， where, order命中index
- Partial Index Scan，也是index scan， where, order命中index, 且match the partial index condition
- bitmap heap scan, bitmap index scan, 以下情况都走bitmap index scan
- "where分开命中2个index"
- "相同index但是是or条件"
- "查询的数据大于pg_relation_size"
- sequential scan , 没命中index
- backward_scan
- Nested Loops join, 命中index, 且是limit数据 | sql
- Hash join, 没有命中index时， 或者无limit，全表join时 | sql
- Merge join, 有order by时 | sql
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12. Full Text Search
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13. Concurrency Control
- 13.1. Introduction | Multiversion Concurrency Control, MVCC | locks | read not conflict write
- 13.2. Transaction Isolation | read commit | repeatable read | serializable
- 13.3. Explicit Locking | table-level lock | row-level lock | page-level lock | deadlocks | advisory locks
- 13.4. Data Consistency Checks at the Application Level
- 13.5. Caveats
- 13.6. Locking and Indexes | page-level locks
- 13.7. ACID | atomicity | consistency | isolation | durability
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14. Performance Tips
- 14.1. Using EXPLAIN
- cost - the first value represents the cost at which the node begins execution, while the second value is the estimated cost for when the execution is done
- rows - the estimated number of rows the node will produce.
- width - the estimated average row size in bytes for the current node.
- actual time - similar to the cost attribute, but represents the execution time in seconds
- rows - the actual number of rows that the node produced.
- loops - the number of times a node got executed
- 14.2. Statistics Used by the Planner
- 14.3. Controlling the Planner with Explicit JOIN Clauses
- 14.4. Populating a Database | copy | prepare execute| Remove Indexes then Recreate indexes| create index in existing data | Remove Foreign Key Constraints
- 14.5. Non-Durable Settings
- 14.1. Using EXPLAIN
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Internal
- Database Cluster, Databases and Tables
- Process and Memory Architecture
- Query Processing
- Foreign Data Wrappers (FDW) and Parallel Query
- Concurrency Control
- VACUUM Processing
- Heap Only Tuple (HOT) and Index-Only Scans
- Buffer Manager
- Write Ahead Logging (WAL)
- Base Backup and Point-In-Time Recovery (PITR)
- Streaming Replication
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I. SQL Commands
- ALTER TABLE — change the definition of a table
- ALTER TYPE — change the definition of a type
- CREATE FOREIGN DATA WRAPPER — define a new foreign-data wrapper
- CREATE FOREIGN TABLE — define a new foreign table
- CREATE FUNCTION — define a new function
- CREATE GROUP — define a new database role
- CREATE INDEX — define a new index
- CREATE TABLE — define a new table
- CREATE TABLE AS — define a new table from the results of a query
- CREATE TRANSFORM — define a new transform
- CREATE TRIGGER — define a new trigger
- CREATE TYPE — define a new data type
- CREATE USER — define a new database role
- CREATE USER MAPPING — define a new mapping of a user to a foreign server
- CREATE VIEW — define a new view
- VALUES — compute a set of rows
MySQL
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1 General Information | SQL Syntax
- [1.2 Typographical and Syntax Conventions
- () , 一组
- [] , options
- | , 枚举， 选一
- {}， 多选
- 1.8 MySQL Standards Compliance | extensions | difference | constraints
- 1.8.1 MySQL Standards Compliance extensions
- 1.8.2 MySQL Standards Compliance difference
- 1.8.2 MySQL Standards Compliance constraints
- [1.2 Typographical and Syntax Conventions
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9 Language Structure
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11 Data Types
- 11.1 Numeric Data Types INTEGER, INT, SMALLINT, TINYINT, MEDIUMINT, BIGINT | Fixed-Point Types |Floating-Point Types
- 11.2 Date and Time Data Types | DATETIME, and TIMESTAMP Types
- 11.3 String Data Types | char | varchar | text | enum | set
- 11.4 Spatial Data Types |Geometry Model
- 11.5 The JSON Data Type
- 11.6 Data Type Default Values
- 11.7 Data Type Storage Requirements
- 11.8 Choosing the Right Type for a Column
- 11.9 Using Data Types from Other Database Engines
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13 SQL Statements
- 13.1 Data Definition Statements
- 13.2 Data Manipulation Statements
- 13.3 Transactional and Locking Statements
- 13.4 Replication Statements
- 13.5 Prepared Statements
- 13.7 Database Administration Statements
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7. Queries - join | full | inner or cross | left | right - join optimizing | inner | outer | semi | anti
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Optimizing
- 8.2 Optimizing SQL Statements
- 8.2.1 Optimizing SELECT Statements | where 易读，避免全表扫 | range
- 8.2.1 Optimizing SELECT Statements | Index lookup | Index Range Scan | Inner hash join | Nested loop inner join
- 8.2.2 Optimizing Subqueries, Derived Tables, View References, and Common Table Expressions
- 8.2.3 Optimizing INFORMATION_SCHEMA Queries
- 8.2.4 Optimizing Performance Schema Queries
- 8.2.5 Optimizing Data Change Statements
- 8.2.6 Optimizing Database Privileges
- 8.2.7 Other Optimization Tips
- 8.3 Optimization Indexes
- 8.3.1 How MySQL Uses Indexes | leftmost prefix |
- B-trees(PRIMARY KEY, UNIQUE, INDEX, and FULLTEXT)
- R-trees(spatial data types)
- 8.3.2 Primary Key Optimization
- 8.3.3 SPATIAL Index Optimization
- 8.3.4 Foreign Key Optimization
- 8.3.5 Column Indexes
- 8.3.6 Multiple-Column Indexes
- 8.3.7 Verifying Index Usage
- 8.3.8 InnoDB and MyISAM Index Statistics Collection
- 8.3.9 Comparison of B-Tree and Hash Indexes
- 8.3.10 Use of Index Extensions
- 8.3.11 Optimizer Use of Generated Column Indexes
- 8.3.12 Invisible Indexes
- 8.3.13 Descending Indexes
- 8.3.14 Indexed Lookups from TIMESTAMP Columns
- 8.3.1 How MySQL Uses Indexes | leftmost prefix |
- 8.4 Optimizing Database Structure | data size | data type | table size | row size
- 8.5 Optimizing for InnoDB Tables
- 8.6 Optimizing for MyISAM Tables
- 8.8 Query Execution Plan
- 8.9 Controlling the Query Optimizer | optimizer hints | index hints | cost
- 8.10 Buffering and Caching
- 8.11 Optimizing Locking Operations | internal lock | table lock | metadata lock | external lock
- 8.2 Optimizing SQL Statements
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12 Functions and Operators
- 12.1 Function and Operator Reference
- 12.2 Type Conversion in Expression Evaluation
- 12.3 Operators | logical | comparison
- 12.4 Control Flow Functions
- 12.5 Numeric Functions and Operators
- 12.6 Date and Time Functions
- 12.7 String Functions and Operators
- 12.8 What Calendar Is Used By MySQL?
- 12.9 Full-Text Search Functions
- 12.10 Cast Functions and Operators
- 12.11 XML Functions
- 12.12 Bit Functions and Operators
- 12.13 Encryption and Compression Functions
- 12.14 Locking Functions
- 12.15 Information Functions
- 12.16 Spatial Analysis Functions
- 12.17 JSON Functions
- 12.20 Aggregate (GROUP BY) Functions
- 12.21 Window Functions
- 12.22 Performance Schema Functions
- 12.23 Internal Functions
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24 Stored Objects
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17 Replication
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23 Partitioning
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4 MySQL Programs
- 4.5.1 mysql — The MySQL Command-Line Client
- 4.5.2 mysqladmin — Client for Administering a MySQL Server
- 4.5.3 mysqlcheck — A Table Maintenance Program
- 4.5.4 mysqldump — A Database Backup Program
- 4.5.5 mysqlimport — A Data Import Program
- 4.5.6 mysqlpump — A Database Backup Program
- 4.5.7 mysqlshow — Display Database, Table, and Column Information
- 4.5.8 mysqlslap — Load Emulation Client
MongoDB
redis
