| Unicode is: | storage for ANY character SET |
| RI examples: | PK's |
| Inner Join is: | used to retrieve records from two or more tables that have matching values in their related columns |
| What does casting do and its errors? | Casting in programming refers to converting a value from one data type to another. It's errors usually include data loss, over and under flow, runtime errors. |
| Types of security: | Hashing |
| What types of databases are there? | Server/Serverless |
| Details about serverless databases? | library that accesses local files through MS Access, SQLite, (which is used on phones), and good for application files. |
| Details about server databases? | Server listens for SQL requests, as well as server based applications/multitier applications. |
| What does RDBMS stand for? | Radical Database Management System |
| What does SQL stand for? | Structure Query Language |
| Types of applications that don't use SQL: | JSON, Document Storage, Object Storage, Image Storage, Columnar of Databases. |
| Cons of Server database: | Infostructure required, (needs server). |
| Cons of SQL: | Doesn't scale horizontally. |
| RDBMS examples: | SQL Server, MySQL, Oracle, SQLite, PostgreSQL, MariaDB |
| No SQL Examples: | Hadoop, DynamoDB, MongoDB, CouchDB, HBase, BigTable |
| Scalability: | What 's Horizontal vs. Vertical |
| Datatypes: | Nvarchar/Varchar
Datetime/Date
Bit
Decimal
int/Bigint |
| RI stands for: | Relationship Integrity (foreign keys & primary keys) |
| Definition of primary keys: | 1 or more columns who's combination ensures row unicity. |
| Definition of foreign keys: | Columns that reference PK's of another table. |
| Composite is: | PK (Primary Key) that is made of 2+ columns |
| Identity is defined as: | A column who's values are incremented for each row. |
| SQLite has: | Serial ID/Sequence/Identity, (generally used for PK's) |
| A one-to-one relationship can be shown as: | Person to passport |
| A one-to-many relationship can be shown as: | Teacher to students |
| A many-to-many relationship can be shown as: | Students and courses |
| A one to many can be drawn as: | FK pointing towards PK, (1 to many relationship) |
| Inner Join is: | used to retrieve records from two or more tables that have matching values in their related columns |
| Outer Join is: | when rows of table A are included without a match in table B. Brings the nulls values. |
| Hashing is: | (Uni)directional operation (FAST) |
| Encryption is: | (Bi)directional (SLOW) |
| Hashing is used for: | Passwords, last 4 of SSN |
| Encryption is used for: | SSN, Sensitive data that must be retrieved |
| Encryption keys are: | Unique by rows |
| Do not store keys in the same database? T or F? | True. Never store keys in the same database. |
| Data table example: | Customer Table |
| Child table example: | Order Address' |
| Reference table example: | Types |
| Delete Cascade on FK is when: | Rows in foreign table(Example: Customer Address) will be automatically deleted when primary key row is deleted (ex: Customer) |
| HARD Delete is when: | Row is gone/removed |
| SOFT Delete is when: | it uses an active/delete bit column to flay a deleted row to preserve data. |
| View is a: | saved query with typically many joins, group-by's or a complex operation. Works like a table but can't be updated or deleted/inserted into the view. |
| Stored procedure is when: | SQL code that does operations in 1 or more tables |
| When to use stored procedure: | typically to a produce complex reports |
| What does N in Nvarchar stand for? | N stands for unicode |
| Unicode is: | storage for ANY character SET |
| RI examples: | PK's |
| Vertical is: | Size of machine |
| Types of security: | Hashing |
| Index is: | a CACHE of row index + HASH of value to speed up lookup of a row to AVOID a ROWSCAN and to speedup database access |
| Bigint size: | 64 bits |
| int size: | 32 bits |
| byte size: | 8 bits |
| Short size: | 16 bits |
