6.1
Database Internals

Storage Engine Fundamentals

Compare row-oriented vs column-oriented storage, page layout, I/O cost, and buffer pool caching

Presets
View
1.0x
users Table (8 rows)
idnameagecitysalary
1Alice28NYC85,000
2Bob34SF120,000
3Carol25LA72,000
4Dave41CHI95,000
5Eve31SEA110,000
6Frank29NYC88,000
7Grace37BOS102,000
8Hank45DEN78,000
Disk Pages (4KB blocks)
ActiveIdle
Row Store Layout(2 pages)
Page 04KB
[1|Alice|28|NYC|85000]
[2|Bob|34|SF|120000]
[3|Carol|25|LA|72000]
[4|Dave|41|CHI|95000]
Page 14KB
[5|Eve|31|SEA|110000]
[6|Frank|29|NYC|88000]
[7|Grace|37|BOS|102000]
[8|Hank|45|DEN|78000]
Buffer Pool (Cache)0/6 slots
Empty - pages will be cached here on access
Metrics
Row Pages Read
0
Col Pages Read
0
Cache Hits
0
Total I/O
0
Buffer Pool
0/6
Query
SELECT *
I/O Log0 ops
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Key Insight

Row Store stores entire rows contiguously on disk pages. Great for OLTP (transactional) workloads where you frequently read/write complete rows.

A single page read retrieves all columns for several rows.