Initial commit of aggregate syntax page

Author: dwdougherty

content/develop/interact/search-and-query/advanced-concepts/aggregation-syntax.md

@@ -0,0 +1,123 @@
+---
+categories:
+- docs
+- develop
+- stack
+- oss
+- rs
+- rc
+- oss
+- kubernetes
+- clients
+description: Order of operations for the FT.AGGREGATE command
+linkTitle: Aggregation syntax
+title: FT.AGGREGATE order of operations
+weight: 2
+---
+
+## Overview
+
+[`FT.AGGREGATE`]({{< relref "/commands/ft.aggregate" >}}) is a powerful command in RQE module for performing advanced data aggregation, filtering, sorting, and transformations on indexed documents. This reference page provides a structured breakdown of syntax, ordering rules, and best practices.
+
+## Syntax and expression ordering
+
+The `FT.AGGREGATE` command processes multiple expressions in a pipeline. Below is the recommended order:
+
+1. `FILTER` – filters raw documents before transformations or aggregation.
+1. `LOAD` – loads additional document attributes.
+1. `APPLY` – applies transformations on fields.
+1. `GROUPBY` – groups results by specific fields.
+1. `REDUCE` – performs aggregations. For example, `SUM`, `COUNT`, and `AVG`.
+1. `SORTBY` – orders the results based on specified fields.
+1. `LIMIT` – restricts the number of results returned.
+
+## Using GROUPBY with multiple REDUCE
+
+`GROUPBY` can be followed by multiple `REDUCE` operations for different aggregations.
+```sh
+FT.AGGREGATE products "*"
+  GROUPBY 1 @category
+  REDUCE COUNT 0 AS product_count
+  REDUCE SUM 1 @price AS total_price
+  REDUCE AVG 1 @rating AS avg_rating
+  SORTBY 2 @total_price DESC
+  LIMIT 0 10
+```
+
+## Using multiple APPLY, GROUPBY, and REDUCE
+
+`APPLY` can be used in various ways before and after `GROUPBY` and `REDUCE`.
+```sh
+FT.AGGREGATE products "*"
+  APPLY "@price - @discount AS final_price"
+  APPLY "@final_price * @quantity AS total_revenue"
+  GROUPBY 1 @category
+  REDUCE SUM 1 total_revenue AS total_category_revenue
+  SORTBY 2 total_category_revenue DESC
+  LIMIT 0 10
+```
+
+## Using FILTER and PARAMS
+
+`FILTER` is used to remove unwanted records, while `PARAMS` allows parameterized queries.
+```sh
+FT.AGGREGATE products "*"
+  PARAMS 2 "min_price" 500 "min_rating" 4.0
+  FILTER "@price >= $min_price"
+  FILTER "@rating >= $min_rating"
+  APPLY "@price * @quantity AS total_value"
+  SORTBY 2 total_value DESC
+  LIMIT 0 10
+```
+
+## Placement of FILTER before and after GROUPBY/APPLY
+
+- **Before GROUPBY:** Removes records before aggregation.
+- **After GROUPBY:** Filters based on aggregated results.
+- **Before APPLY:** Ensures calculations are applied only to certain records.
+- **After APPLY:** Filters computed values.
+
+## Using LOAD after GROUPBY/REDUCE
+
+`LOAD` is generally used **before** `GROUPBY`, but in some cases, it can be used afterward to retrieve document metadata.
+```sh
+FT.AGGREGATE products "*"
+  GROUPBY 1 @category
+  REDUCE COUNT 0 AS product_count
+  REDUCE SUM 1 @price AS total_price
+  WITHCURSOR COUNT 5
+```
+
+## Placement rules for specific parameters
+
+| Parameter | Placement |
+|-----------|----------------|
+| `TIMEOUT` | Can be placed anywhere |
+| `LIMIT` | Must be at the end |
+| `WITHCURSOR` | Must be at the end |
+| `SCORER` | Can be placed anywhere |
+| `ADDSCORES` | Must be before sorting |
+| `DIALECT` | Must be at the end |
+
+## LIMIT and WITHCURSOR are mutually exclusive
+
+`LIMIT` returns immediate results, while `WITHCURSOR` retrieves results incrementally.
+```sh
+FT.AGGREGATE products "*"
+  GROUPBY 1 @category
+  REDUCE COUNT 0 AS product_count
+  WITHCURSOR COUNT 5
+```
+
+## Summary
+
+- `GROUPBY` allows multiple `REDUCE` functions.
+- `APPLY` can be positioned before or after grouping.
+- `FILTER` placement affects results significantly.
+- `LOAD` after `GROUPBY` is only useful in specific cases.
+- `LIMIT` and `WITHCURSOR` **cannot** be used together.
+
+For further reference:
+- [`FT.AGGREGATE` command page](https://redis.io/docs/latest/commands/ft.aggregate/)
+- [RQE source code](https://github.com/RediSearch/RediSearch/tree/master/src/aggregate)
+

content/develop/interact/search-and-query/advanced-concepts/autocomplete.md

@@ -12,7 +12,7 @@ categories:
 description: Learn how to use the autocomplete feature of Redis for efficient prefix-based suggestion retrieval.
 linkTitle: Autocomplete
 title: Autocomplete with Redis
-weight: 1
+weight: 2
 ---
 
 ## Overview

content/develop/interact/search-and-query/advanced-concepts/stopwords.md

@@ -12,7 +12,7 @@ categories:
 description: Stop words support
 linkTitle: Stop words
 title: Stop words
-weight: 1
+weight: 2
 ---
 
 Redis Stack has a default list of [stop words](https://en.wikipedia.org/wiki/Stop_words). These are words that are usually so common that they do not add much information to search, but take up a lot of space and CPU time in the index.