Advanced PostgreSQL: Indexing, Partitioning, Replication · Pelajaran

Menerapkan Partisi Daftar

Pahami cara menyiapkan partisi daftar dengan mengelompokkan data berdasarkan nilai diskret tertentu dalam kolom.

Menerapkan Partisi Daftar adalah pelajaran Advanced PostgreSQL: Indexing, Partitioning, Replication gratis di CoddyKit. Ini adalah pelajaran 3 dari 4. Kamu bisa membaca pelajaran lengkapnya di bawah secara gratis — lalu praktikkan langsung di browser dengan editor kode bawaan dan tutor AI 24/7. Ini adalah bagian dari jalur belajar Advanced PostgreSQL: Indexing, Partitioning, Replication, dan progresmu tersinkronisasi di web dan aplikasi CoddyKit. Kursus Advanced PostgreSQL: Indexing, Partitioning, Replication mencakup 4 pelajaran total.

Bagian dari pelajaran ini belum diterjemahkan dan ditampilkan dalam bahasa Inggris.

What is List Partitioning?

Welcome! In this lesson, we'll dive into List Partitioning, a powerful way to organize your data in PostgreSQL.

List partitioning divides a table based on discrete values in a specified column. Think of it as categorizing your data into distinct groups.

List vs. Range: A Quick Look

You might recall Range Partitioning from a previous lesson, which divides data based on a *range* of values (e.g., dates, IDs).

List partitioning is different: it uses specific, distinct values. For example, you could partition by country_code ('US', 'CA', 'MX') or order_status ('PENDING', 'SHIPPED', 'CANCELLED').

Choosing Your Partition Key

The column you choose to partition by is called the partition key. For list partitioning, this column should have a finite and manageable set of distinct values.

Good candidates: Country codes, product categories, order statuses.
Poor candidates: Timestamps, large text fields, unique IDs (too many distinct values).

Setting Up the Parent Table

First, we create the main table, known as the parent table. We specify PARTITION BY LIST and indicate the column that will serve as our partition key.

Let's create a sales table partitioned by country_code:

CREATE TABLE sales (
    sale_id SERIAL,
    product_id INT,
    country_code CHAR(2),
    amount NUMERIC(10, 2),
    sale_date DATE
) PARTITION BY LIST (country_code);

Defining Your Partitions

Once the parent table is ready, we create individual child partitions. Each child partition is a separate table that stores rows for specific values of the partition key.

Here, we create partitions for sales in the 'US' and 'CA':

CREATE TABLE sales_us PARTITION OF sales
FOR VALUES IN ('US');

CREATE TABLE sales_ca PARTITION OF sales
FOR VALUES IN ('CA');

Data Insertion in Action

When you insert data into the parent sales table, PostgreSQL automatically directs each row to the correct child partition based on its country_code value.

Let's add some sales data and then check the individual partitions:

INSERT INTO sales (product_id, country_code, amount, sale_date) VALUES
(101, 'US', 150.75, '2023-01-05'),
(102, 'CA', 200.00, '2023-01-06'),
(103, 'US', 75.20, '2023-01-07');

SELECT * FROM sales_us;
SELECT * FROM sales_ca;

Inspecting Your Partitions

It's good practice to verify that your partitions are correctly linked to the parent table. You can query PostgreSQL's catalog tables to see the inheritance structure.

This query lists child tables for 'sales':

SELECT relnamespace::regnamespace AS parent_schema,
       relname AS parent_table,
       c.relname AS child_table
FROM pg_class p
JOIN pg_inherits i ON p.oid = i.inhparent
JOIN pg_class c ON i.inhrelid = c.oid
WHERE p.relname = 'sales';

Expanding Your Partition Scheme

As your business expands or new data categories emerge, you can easily add new partitions to your existing scheme without downtime.

Let's add a partition for Mexico ('MX') sales and insert some data:

CREATE TABLE sales_mx PARTITION OF sales
FOR VALUES IN ('MX');

INSERT INTO sales (product_id, country_code, amount, sale_date) VALUES
(104, 'MX', 120.50, '2023-01-08');

SELECT * FROM sales_mx;

Handling Unknown Values with DEFAULT

What happens if you insert a country_code that isn't explicitly covered by a partition (e.g., 'GB')?

You can create a default partition to catch all values that don't match any other defined list. This prevents errors for unexpected data.

CREATE TABLE sales_default PARTITION OF sales
DEFAULT;

INSERT INTO sales (product_id, country_code, amount, sale_date) VALUES
(105, 'GB', 99.99, '2023-01-09');

SELECT * FROM sales_default;

List Partitioning Quiz

Consider a table orders partitioned by list on the status column, which can be 'NEW', 'PROCESSING', 'SHIPPED', or 'CANCELLED'.

List Partitioning Summary

We've covered how to implement list partitioning in PostgreSQL. You learned to:

Define a parent table with PARTITION BY LIST.
Create child partitions using FOR VALUES IN.
Route data automatically upon insertion.
Add new partitions and handle unspecified values with a DEFAULT partition.

List partitioning is ideal for data with discrete, categorical values, helping organize and query your data more efficiently.

Pertanyaan yang Sering Diajukan

Apakah pelajaran “Menerapkan Partisi Daftar” gratis?

Ya — teks lengkap “Menerapkan Partisi Daftar” gratis dibaca di sini di web. Untuk praktiknya secara interaktif (editor kode bawaan dan tutor AI 24/7) dan buka sisa kursus Advanced PostgreSQL: Indexing, Partitioning, Replication, upgrade ke CoddyKit PRO. Kursus Advanced PostgreSQL: Indexing, Partitioning, Replication mencakup 4 pelajaran total.

Apa yang akan aku pelajari di “Menerapkan Partisi Daftar”?

Pahami cara menyiapkan partisi daftar dengan mengelompokkan data berdasarkan nilai diskret tertentu dalam kolom. Kamu berlatih Advanced PostgreSQL: Indexing, Partitioning, Replication dengan kode praktik yang langsung kamu jalankan di browser, dan tutor AI 24/7 menjawab pertanyaanmu saat kamu mengerjakan pelajaran ini.

Apakah aku perlu pengalaman untuk memulai Advanced PostgreSQL: Indexing, Partitioning, Replication?

Tidak diperlukan pengalaman sebelumnya. Advanced PostgreSQL: Indexing, Partitioning, Replication di CoddyKit dirancang untuk pemula hingga pelajar tingkat lanjut, jadi kamu bisa memulai di sini atau dari awal dan belajar sesuai kecepatan kamu sendiri. Ini adalah pelajaran 3 dari 4.

Berapa lama pelajaran “Menerapkan Partisi Daftar” memakan waktu?

Sebagian besar pelajaran CoddyKit memakan waktu sekitar 5–10 menit. Setiap pelajaran ringkas dan interaktif, jadi kamu membuat kemajuan stabil dan melanjutkan dari tempat kamu tinggalkan di web dan aplikasi.

Bisakah aku menulis dan menjalankan kode dalam pelajaran Advanced PostgreSQL: Indexing, Partitioning, Replication ini?

Ya. Setiap pelajaran Advanced PostgreSQL: Indexing, Partitioning, Replication menyertakan editor kode bawaan, jadi kamu menulis dan menjalankan kode nyata langsung di browser dan mendapatkan umpan balik AI instan — tidak diperlukan penyiapan lokal.

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