Syntax and examples of window funnel functions - Simple Log Service

Simple Log Service provides window funnel functions. You can use the functions to analyze data, such as user behavior, application traffic, and product goal conversion. This topic describes the syntax of window funnel functions. This topic also provides examples on how to use the functions.

The following table describes the window funnel functions that are supported by Simple Log Service.

Important If you want to use strings in analytic statements, you must enclose strings in single quotation marks (''). Strings that are not enclosed or enclosed in double quotation marks ("") indicate field names or column names. For example, 'status' indicates the status string, and status or "status" indicates the status log field.

Function

Syntax

Description

Supported in SQL

Supported in SPL

window_funnel function

window_funnel(sliding_window, timestamp, event_id, ARRAY[event_list01, event_list02...])

Searches for an event chain in a sliding time window and counts the maximum number of consecutive events in the event chain.

If the value of the event_id parameter is specified in an event chain, you can use this syntax.

√

window_funnel(sliding_window, timestamp, ARRAY[event_id=event_list01, event_id=event_list02...])

Searches for an event chain in a sliding time window and counts the maximum number of consecutive events in the event chain.

If the value of the event_id parameter is not specified in an event chain and you want to use a custom value for the event_id parameter, you can use this syntax, which is more flexible.

√

Implementation

Window funnel functions are used to search for an event chain in a sliding time window and count the maximum number of consecutive events in the event chain. Window funnel functions start the count from the first event in the event chain that you specify, check the events in sequence, and then return the maximum number of consecutive events.

A window funnel function works based on the following algorithm:

The function starts the count from the first event in the event chain and sets the initial value of the event counter to 1. Then, the sliding time window starts.
In the sliding time window, if events in the event chain occur in sequence, the event counter is incremented.
In the sliding time window, if the sequence of events in the event chain is disrupted, the event counter stops. The search stops, and a new search starts. The maximum number of consecutive events is counted until the end of the last search.
At the end of the last search, if multiple values of the count exist, the function returns the maximum value of the count. The maximum value of the count indicates the maximum number of consecutive events.

For example, you specify a sliding time window of 100 seconds and the following pattern for the event chain: Event 1, Event 2, Event 3, Event 4, and Event 5. However, the events in the event chain occur in the following sequence: Event 1, Event 2, Event 4, Event 5, Event 1, and Event 3. In the sliding time window, the maximum number of consecutive events is 2. A value of 2 indicates the sequential relationship between Event 1 and Event 2.

Important

The function must start the count from the first event in the event chain. For example, if the function starts the count in the sequence of Event 2, Event 3, and Event 4, the function returns 0.
The function must count all events that occur in the event chain. For example, Event 4 occurs in the sliding time window but Event 3 does not. In this case, this search is not involved in counting the maximum number of consecutive events.

窗口漏斗函数

Syntax

The following table describes the window funnel functions that are supported by Simple Log Service.

If the value of the event_id parameter is specified in an event chain, you can use the following syntax:
```
window_funnel(sliding_window, timestamp, event_id, ARRAY[event_list01, event_list02...])
```
If the value of the event_id parameter is not specified in an event chain and you want to use a custom value of the event_id parameter, you can use the following syntax, which is more flexible:
```
window_funnel(sliding_window, timestamp, ARRAY[event_id=event_list01, event_id=event_list02...])
```

Parameters

Parameter	Description
sliding_window	The sliding time window. Unit: seconds. The value of this parameter is of the bigint type.
timestamp	The timestamp. Unit: seconds. The value of this parameter is of the bigint type. We recommend that you use the built-in __time__ field of Simple Log Service.
event_id	The name of the log field. The value of this parameter is the name of an event. Example: Event A, Event B, or Event C. The value of this parameter is of the varchar type.
event_list	The custom event chain, which can contain up to 32 events. The value of this parameter is of the array type. Examples: ARRAY['A', 'B', 'C'] ARRAY[event_id='A', event_id='B', event_id='C']

Examples

An e-commerce store hosted a promotional activity and analyzed the conversion performance of the activity by using window funnel functions. The conversion process consists of three steps: browsing information about a commodity, adding the commodity to the online shopping cart, and then purchasing the commodity. The following figure shows a sample log that is collected by Simple Log Service.

漏斗函数

Log field	Description
behavior_type	The type of user behavior. Valid values: pv: Browse information about a commodity. cart: Add a commodity to the online shopping cart. buy: Purchase a commodity.
category_id	The category ID of the commodity.
item_id	The ID of the commodity.
timestamp	The point in time at which the user behavior occurred.
user_id	The ID of the user.

Example 1

Analyze the purchase behavior that users performed within 24 hours.

Query statement

* |
SELECT
  user_id,
  window_funnel(
    86400,
    timestamp,
    ARRAY [behavior_type='pv', behavior_type='cart',behavior_type='buy']
  ) AS levels
GROUP BY
  user_id
ORDER BY
  user_id
LIMIT
  1000

Query and analysis results
- The value of the levels field is 3 for user 24. The user completes the purchase in the sequence of browsing information about a commodity, adding the commodity to the online shopping cart, and then purchasing the commodity.
- The value of the levels field is 2 for user 14. The user browses information about a commodity and adds the commodity to the online shopping cart but does not complete the purchase.

Example 2

Analyze the numbers of users who have different types of user behavior.

Query statement

* |
SELECT
  levels,
  count,
  sum(count) over(
    ORDER BY
      levels DESC
  ) AS total
FROM  (
    SELECT
      levels,
      count(1) AS count
    FROM      (
        SELECT
          user_id,
          window_funnel(
            86400,
            timestamp,
            ARRAY [behavior_type='pv', behavior_type='cart',behavior_type='buy']
          ) AS levels
        FROM          log
        GROUP BY
          user_id
      )
    GROUP BY
      levels
    ORDER BY
      levels
  )

Query and analysis results
- The number of users who browse information about a commodity is 513,194. The number of users who do not continue their purchase process after they browse information about the commodity is 138,491.
- The number of users who add the commodity to the online shopping cart is 374,703. The number of users who do not continue the purchase process after they add the commodity to the online shopping cart is 198,642.
- The number of users who purchase the commodity is 176,061.

Example 3

Calculate the conversion rate of this promotional activity.

Absolute conversion rate: the proportion of the users who perform a type of user behavior to the total number of users.
Relative conversion rate: the proportion of the users who perform a type of user behavior to the users who perform a different type of user behavior. The latter type of user behavior occurred before the former type of user behavior.

Query statement

* |
SELECT
  *,
  100.0 * total /(sum(count) over()) AS "Absolute conversion rate",
  if(
    lag(total, 1, 0) over() = 0,
    100,
    (100.0 * total / lag(total, 1, 0) over())
  ) AS "Relative conversion rate"
FROM  (
    SELECT
      levels,
      count,
      sum(count) over(
        ORDER BY
          levels DESC
      ) AS total
    FROM      (
        SELECT
          levels,
          count(1) AS count
        FROM          (
            SELECT
              user_id,
              window_funnel(
                86400,
                timestamp,
                ARRAY [behavior_type='pv', behavior_type='cart',behavior_type='buy']
              ) AS levels
            FROM              log
            GROUP BY
              user_id
          )
        GROUP BY
          levels
      )
    ORDER BY
      levels
  )

Query and analysis results
- Query and analysis results in a table
- Query and analysis results in a funnel chart