From 9349774454232ae0017982fe16459ae60528353a Mon Sep 17 00:00:00 2001
From: Andres Taylor <andres@planetscale.com>
Date: Wed, 27 Nov 2024 13:45:05 +0100
Subject: [PATCH] feat: better report for txs

Signed-off-by: Andres Taylor <andres@planetscale.com>
---
 go/summarize/markdown.go               |  8 ++++++++
 go/summarize/summarize-transactions.go | 28 +++++++++++++++++---------
 go/summarize/summary.go                |  4 ++++
 3 files changed, 31 insertions(+), 9 deletions(-)

diff --git a/go/summarize/markdown.go b/go/summarize/markdown.go
index 94b80fe..3af98fd 100644
--- a/go/summarize/markdown.go
+++ b/go/summarize/markdown.go
@@ -242,6 +242,14 @@ func renderTransactions(md *markdown.MarkDown, transactions []TransactionSummary
 			md.Printf("%d. **%s** on `%s`  \n", i+1, strings.ToTitle(query.Type), query.Table)
 			md.Printf("   Predicates: %s\n\n", strings.Join(query.Predicates, " AND "))
 		}
+
+		md.PrintHeader("Shared Predicate Values", 3)
+		for idx, join := range tx.Joins {
+			md.Printf("* Value %d applied to:\n", idx)
+			for _, s := range join {
+				md.Printf("  - %s\n", s)
+			}
+		}
 		if i != len(transactions)-1 {
 			md.Printf("---\n")
 		}
diff --git a/go/summarize/summarize-transactions.go b/go/summarize/summarize-transactions.go
index 6e16f6c..809bc45 100644
--- a/go/summarize/summarize-transactions.go
+++ b/go/summarize/summarize-transactions.go
@@ -17,6 +17,10 @@ limitations under the License.
 package summarize
 
 import (
+	"fmt"
+	"maps"
+	"slices"
+
 	"vitess.io/vitess/go/slice"
 
 	"github.com/vitessio/vt/go/transactions"
@@ -24,26 +28,25 @@ import (
 
 func summarizeTransactions(s *Summary, txs []transactions.Signature) error {
 	for _, tx := range txs {
-		patterns, interesting := summarizeQueries(tx.Queries)
-		if !interesting {
+		patterns, joins := summarizeQueries(tx.Queries)
+		if len(joins) == 0 {
 			continue
 		}
 		s.transactions = append(s.transactions, TransactionSummary{
 			Count:   tx.Count,
 			Queries: patterns,
+			Joins:   joins,
 		})
 	}
 	return nil
 }
 
-func summarizeQueries(queries []transactions.Query) (patterns []QueryPattern, interesting bool) {
+func summarizeQueries(queries []transactions.Query) (patterns []QueryPattern, joins [][]string) {
+	columnJoins := map[int][]string{}
 	for _, q := range queries {
-		if !interesting {
-			// Check if any of the predicates are interesting
-			for _, predicate := range q.Predicates {
-				if predicate.Val >= 0 {
-					interesting = true
-				}
+		for _, predicate := range q.Predicates {
+			if predicate.Val >= 0 {
+				columnJoins[predicate.Val] = append(columnJoins[predicate.Val], fmt.Sprintf("%s.%s", q.AffectedTable, predicate.Col))
 			}
 		}
 		patterns = append(patterns, QueryPattern{
@@ -53,5 +56,12 @@ func summarizeQueries(queries []transactions.Query) (patterns []QueryPattern, in
 			UpdatedColumns: q.UpdatedColumns,
 		})
 	}
+	joinKeys := slices.Collect(maps.Keys(columnJoins))
+	slices.Sort(joinKeys)
+
+	for _, key := range joinKeys {
+		cols := columnJoins[key]
+		joins = append(joins, cols)
+	}
 	return
 }
diff --git a/go/summarize/summary.go b/go/summarize/summary.go
index 8c438bd..7cf2d0e 100644
--- a/go/summarize/summary.go
+++ b/go/summarize/summary.go
@@ -52,6 +52,10 @@ type (
 	TransactionSummary struct {
 		Count   int
 		Queries []QueryPattern
+
+		// Joins contain a list of columns that are joined together.
+		// Each outer slice is one set of columns that are joined together.
+		Joins [][]string
 	}
 
 	QueryPattern struct {