How to Filter Data in ParadeDB with PostgreSQL WHERE Clause

Galaxy Glossary

How do I filter data in ParadeDB using the PostgreSQL WHERE clause?

The WHERE clause filters rows that satisfy a Boolean condition, returning only the data you need from ParadeDB.

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Description

Example H2

Example H3

Why should I use the WHERE clause to filter data?

Filtering early trims result sets, speeds queries, and lowers memory usage. ParadeDB follows PostgreSQL rules, so every standard WHERE expression— comparisons, pattern matching, subqueries— works unchanged.

What is the basic syntax for filtering?

Use SELECT column_list FROM table WHERE condition;. Combine multiple conditions with AND, OR, NOT, and parentheses for clarity.

How do I compare numeric, text, and date columns?

Operators = <> > >= < <= work on numbers, dates, and text. Use ILIKE for case-insensitive text, BETWEEN ... AND ... for ranges, and IN (...) for lists.

Can I filter across related tables?

Yes. JOIN tables first, then add your WHERE clause. The planner reorders joins for efficiency, so filters are still pushed down.

How do I filter vector search results?

Combine ParadeDB's vector operators with traditional predicates: ... WHERE embedding <=> embed('shoes') < 0.3 AND stock > 0. Metadata filters narrow expensive similarity searches.

Example: list recent high-value orders

SELECT o.id, c.name, o.total_amount FROM Orders AS o JOIN Customers AS c ON c.id = o.customer_id WHERE o.order_date >= CURRENT_DATE - INTERVAL '30 days' AND o.total_amount >= 500;

Best practices for effective filtering

Index columns used in WHERE. Avoid wrapping indexed columns in functions; use expression indexes if needed. Place selective predicates first when chaining with AND for readability.

What mistakes should I avoid?

Using leading wildcards

LIKE '%shoe%' skips b-tree indexes. Create a trigram/GiST index or use full-text search instead.

Filtering with HAVING unnecessarily

Using HAVING when no aggregates are present slows execution. Put non-aggregate filters in WHERE.

Why How to Filter Data in ParadeDB with PostgreSQL WHERE Clause is important

How to Filter Data in ParadeDB with PostgreSQL WHERE Clause Example Usage


-- Find the five most similar shoes in stock under $150
SELECT p.id, p.name, p.price, p.stock
FROM Products AS p
WHERE p.name ILIKE '%shoe%'
  AND p.price <= 150
ORDER BY p.embedding <=> embed('running shoe')
LIMIT 5;

How to Filter Data in ParadeDB with PostgreSQL WHERE Clause Syntax


SELECT column_list
FROM table_name
WHERE condition1
  [AND | OR | NOT condition2]
  [AND vector_column <=> embed('search text') < threshold]
ORDER BY column
LIMIT n;

-- Ecommerce examples
-- 1. Customers who signed up this year
SELECT id, name, email
FROM Customers
WHERE created_at >= DATE '2024-01-01';

-- 2. Orders over $1,000 for a given customer
SELECT id, total_amount
FROM Orders
WHERE customer_id = 42
  AND total_amount > 1000;

-- 3. Low-stock products
SELECT id, name, stock
FROM Products
WHERE stock < 5;

Common Mistakes

Leading wildcards in LIKE patterns prevent index use. Replace "LIKE '%term%'" with trigram indexes or full-text search for performance.
Placing simple filters in HAVING rather than WHERE forces unnecessary aggregation. Move non-aggregate conditions back to WHERE.