Handle Unusually Large Histories with Data Skew Protection

You do not always need to analyze every record or give AI every result to answer a question. zinzu provides controls that reduce how much work is done at different stages.

3 min readProduct documentationControl Analysis Costs in zinzu
ControlIn plain languageWhat it controls
Data skew protectionLeave out unusually large histories that could dominate the work.Which EventOwners reach sequence analysis.
SamplingAnalyze a smaller group of owners first.How many EventOwners are included in the query.
AI sequence limitGive AI a few examples instead of every matching sequence.How much sequence data is included in an AI request.

EventOwner means whoever or whatever you group records by: a customer, order, request, device, or application.

These controls can reduce processing work, but they are not a fixed spending cap. Cost also depends on the data read, query, compute resources, and AI request.

What Is Data Skew?

Imagine checking 1,000 customer folders. Most contain 20 pages, but one contains a million pages. That one folder can take far more work than the others.

The same thing can happen in your data. Most EventOwners may have a modest number of records, while a few have extremely large histories. This uneven distribution is called data skew.

For example, a busy device, automated account, or shared identifier might generate far more records than a typical owner.

How It Works

When enabled, zinzu counts each owner’s source records within the selected query time range, across the sources used by the query.

If an owner’s total exceeds the configured threshold, zinzu excludes that owner from sequence analysis for that run.

Example threshold:50,000 records per EventOwner

EventOwnerRecords in the selected rangeWhat happens
Customer A120Eligible for analysis.
Customer B12,000Eligible for analysis.
Customer C50,000Eligible; exactly the threshold is allowed.
Customer D80,000Excluded from sequence analysis.

Customer D’s entire history is excluded for that run. zinzu does not simply retain its first 50,000 records.

If one owner has 30,000 records in one source and 25,000 in another, the combined 55,000 exceeds this example threshold.

Why It Helps

Excluding exceptionally large histories can reduce the work and memory needed for sequence matching and prevent a small number of owners from dominating processing.

Counting those records still requires work. This protection does not mean the excluded data costs nothing to read.

When to Use It

Use it when you want to explore typical behavior and a few unusually large histories are making analysis expensive.

Review exclusions carefully when investigating heavy users, automated activity, fraud, or busy devices—the excluded owners may be the ones you need.

Important Notes

  • The threshold applies to source records, not just records that match your event definitions.
  • It applies within the selected query range, not the owner’s entire lifetime.
  • No records are deleted from your source tables.
  • Excluded owners do not contribute matches to that query.
  • 50,000 is an example threshold, not a universal default.

Current availability:Data skew protection is implemented in the backend through query configuration. The reviewed query-builder UI does not expose a setting for it. It is disabled when no configuration enables it.

Conceptual threshold example. The supplied guide describes data skew protection as backend configuration; this is not a query-builder setting.
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