Identifying access patterns first in DynamoDB - Step-by-Step Execution

Concept Flow - Identifying access patterns first

Start: Understand app needs

↓

List all data queries

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Identify access patterns

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Design table keys and indexes

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Implement and test queries

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Optimize based on usage

First, understand what data your app needs and how it will ask for it. Then design your database keys and indexes to match those access patterns for fast queries.

Execution Sample

DynamoDB

Access patterns:
- Get user by ID
- List orders by user
- Find products by category

Design keys:
- PK: UserID
- GSI: Category as PK

Shows identifying queries and designing keys to match them for efficient DynamoDB access.

Execution Table

Step	Action	Input/State	Output/Decision
1	List app queries	App features	User by ID, Orders by user, Products by category
2	Identify access patterns	Queries list	Access patterns: get user, list orders, find products
3	Design primary key	Access pattern: get user	PK = UserID
4	Design secondary index	Access pattern: find products	GSI with Category as PK
5	Implement table	Keys designed	Table ready with keys and indexes
6	Test queries	Table implemented	Queries run efficiently
7	Optimize	Query performance	Adjust keys or add indexes if needed
8	End	All access patterns supported	Design complete

💡 All access patterns identified and table designed to support them efficiently

Variable Tracker

Variable	Start	After Step 2	After Step 4	Final
AccessPatterns	[]	[get user, list orders, find products]	[get user, list orders, find products]	[get user, list orders, find products]
PrimaryKey	null	null	UserID	UserID
SecondaryIndexes	[]	[]	[GSI: Category]	[GSI: Category]

Key Moments - 2 Insights

Why do we list all queries before designing keys?

Listing queries first (see execution_table step 1) helps us understand exactly how the app will access data, so we can design keys that make those queries fast.

Why do we create secondary indexes?

Secondary indexes (step 4) let us efficiently query data in ways the primary key doesn't support, like finding products by category.

Visual Quiz - 3 Questions

Look at the execution_table, what is the primary key designed for?

A To find products by category

B To get user by ID

C To list orders by user

D To optimize query speed

💡 Hint

Check step 3 in execution_table where primary key is designed for 'get user' access pattern

At which step do we test if queries run efficiently?

A Step 4

B Step 2

C Step 6

D Step 7

💡 Hint

Look at execution_table step 6 where queries are tested

If we add a new query to find orders by date, what should we do next?

A Add a new secondary index for date

B Change the primary key to date

C Ignore it because primary key covers all

D Delete existing indexes

💡 Hint

Refer to variable_tracker and execution_table steps 4 and 7 about adding indexes to support new access patterns

Concept Snapshot

Identify all app queries first
List access patterns clearly
Design primary key for main query
Add secondary indexes for others
Test queries for efficiency
Adjust design as needed

Full Transcript

To design a DynamoDB table well, first list all the ways your app will ask for data. These are your access patterns. Then design your primary key to support the most common or important query. For other queries, add secondary indexes. Implement the table and test your queries to make sure they run fast. If needed, adjust keys or add more indexes. This approach ensures your database matches your app's needs and performs well.