Column databases

columnar or column oriented databases

Hussein Nasser video

Examples

• Apache Cassandra
• Sentry uses a columnar database too??

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SELECT * FROM table WHERE id=1

Writes (and updates) are very slow

Writes and reads are complex

Row vs Column database

When to use row based

• default, handles most cases well enough
  • the power drill of databases
• read & write
• OLTP
  • online transaction processing
  • concurrent transactions
    • online banking, shopping, texting
• efficient queries with multiple columns

When to use column database

• data lakes and warehouses
  • data is static
  • need to aggregate a lot
• when you don't have a lot of writes
• OLAP
  • online analytical processing
  • business insights from data

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Last update: 2023-04-24