IDB
B+ Tree Lab
page 16K
Structure & operations
3
01
Engine
—
max rec
1× slow
2× normal
4× fast
Collapse all
Expand all
Rebuild
What this panel does
02
DML
0 rows
INSERT
UPDATE
DELETE
Bulk insert
INSERT vs UPDATE
03
Query
idle
Find by PK
Bookmark lookup
Range scan
Clear highlighted path
What-if
Predict
—
Apply for real
Dismiss
What a lookup highlights
Storage & recovery
2
04
Buffer Pool
0/5
HIT
0
MISS
0
hit rate
—
Show MISS then HIT
Flush the pool
How to use it
05
Redo Log (WAL)
LSN 0x1A00
current
0x1A00
checkpoint
0x1A00
dirty
0
Checkpoint
How to use it
Transactions & concurrency
4
06
MVCC / Transactions
idle
Session
A
B
BEGIN
COMMIT
Isolation
RR
Repeatable Read
RC
Read Committed
One Read View for the whole transaction.
How to use it
07
Locks
—
X exclusive
S shared
REC record
GAP gap
NEXT-KEY
Acquire lock
Release
How to use it
08
Purge Queue
—
Run purge
Merge pages
How to use it
09
Undo Log
TRX: 0x2A10
Build a version chain
How to use it
Tools
3
10
Step Mode
off
playback
Continuous
Step
Step pauses every action until you ask for the next one.
Narration
On
Off
Explain each step on the canvas
How to use it
11
State I/O
—
Export JSON
Copy
Import JSON
Reset
Compare shapes
Arm compare
Before / after
How to use it
12
Share
—
Save PNG
Save PDF
Save SVG
How to use it
EN
中文
System
Light
Dark
PK
Clustered index
SK
Secondary index
Guide
−
100%
+
STEP
—
Waiting for the next step
Next ▸
Exit
RANGE
—
⣿
0
rows collected
leaf pages
0
next hops
0
disk I/O
0
WALKTHROUGH
⣿
LEGEND
⣿
Before / after
同步滚动
Fit
−
100%
+
esc
Before
After
Get started in 30 seconds
esc
30-second tour
Vocabulary first
If the animation is too fast, switch to Step