RediSearch - ioredis client lib

Summary

I'll be demonstrating various Redis Search operations with the ioredis (Nodejs) client lib in this post.

Data Set Creation

A random set of objects are created and are then saved in Redis as hash sets.

    const pipeline = client.pipeline();
    for (let i=0; i < NUM; i++) {
        const colors = (COLORS.sort(() => .5 - Math.random())).slice(0, Math.floor(Math.random() * COLORS.length))
        const fields = {
            'textField': `text${Math.floor(Math.random() * NUM)}`, 
            'numericField': Math.floor(Math.random() * NUM), 
            'tagField': colors
        };
        await pipeline.hmset(`item:${i}`, fields);
    }
    await pipeline.exec();

Index Creation

    await client.call('FT.CREATE', 'idx', 'ON', 'HASH', 'PREFIX', '1', 'item:', 'SCHEMA', 
        'textField', 'TEXT', 'SORTABLE',
        'numericField', 'NUMERIC', 'SORTABLE',
        'tagField', 'TAG'
    );

Search Operations

	//Search for exact match in a Text field
    let result = await client.call('FT.SEARCH', 'idx', '@textField:text1');
 
    //Search for a range in a Numeric field
    result = await client.call('FT.SEARCH', 'idx', '@numericField:[1,3]');
 
    //Search for a match in a Tag Field
    result = await client.call('FT.SEARCH', 'idx', '@tagField:{blue}');

Aggregation Operations

    //Aggregate on a text field across all hashes in the index
    let result = await client.call('FT.AGGREGATE', 'idx', '*', 'GROUPBY', '1', '@textField', 
        'REDUCE', 'COUNT', '0', 'AS', 'CNT');
        
    //Search on a numeric range and then apply the SQRT function to a numeric field in the matches
    const upper = Math.floor(Math.random() * NUM) + 1;
    result = await client.call('FT.AGGREGATE', 'idx', `@numericField:[0,${upper}]`, 
        'APPLY', 'SQRT(@numericField)', 'AS', 'SQRT');
        
    
    //Search for logical OR of two tag values and use a CURSOR.  Limit return
    //to 2 values to illustrate looping on a cursor.
    result = await client.call('FT.AGGREGATE', 'idx', '@tagField:{ yellow | red }', 
        'LOAD', '3', '@textField', '@numericField', '@tagField',
        'WITHCURSOR', 'COUNT', '2'
    );
    console.log('FT.AGGREGATE idx @tagField:{ yellow | red } LOAD 3 @textField @numericField @tagField WITHCURSOR COUNT 2');
    let items = result[0];
    let cursor = result[1];
    while (true) {
        for (let item of items) {
            if (Array.isArray(item)) {
                console.log(JSON.stringify(item))
            }
        }
        if (cursor) {
            result = await client.call('FT.CURSOR', 'READ', 'idx', cursor, 'COUNT', '2');
            items = result[0];
            cursor = result[1];
        }
        else {
            break;
        }
    }

Index Alteration

    await client.call('FT.ALTER', 'idx', 'SCHEMA', 'ADD', 'newField', 'TEXT', 'SORTABLE');
    let result = await client.call('FT.INFO', 'idx');

Source

https://github.com/Redislabs-Solution-Architects/ioredis-search

Copyright ©1993-2024 Joey E Whelan, All rights reserved.