From c69d36d057efac1755c9a622e79ffbe03d8c74ca Mon Sep 17 00:00:00 2001
From: Ahir Reddy <ahirreddy@gmail.com>
Date: Wed, 21 Aug 2024 15:51:17 -0700
Subject: [PATCH 1/2] min chunk

---
 bin/pt-online-schema-change | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/bin/pt-online-schema-change b/bin/pt-online-schema-change
index d7d118d95..0199070f0 100755
--- a/bin/pt-online-schema-change
+++ b/bin/pt-online-schema-change
@@ -10099,6 +10099,12 @@ sub main {
    my $avg_rate   = 0;  # rows/second
    my $limit      = $o->get('chunk-size-limit');  # brevity
    my $chunk_time = $o->get('chunk-time');        # brevity
+   my $min_chunk_size = $o->get('dynamic-min-chunk-size');
+   # Exit if the user passes a value less than 1
+   if ($min_chunk_size < 1) {
+      _die("The value passed for --dynamic-min-chunk-size is less than 1. Please pass a value greater than or equal to 1.");
+   }
+   print ts("Minimum chunk size is $min_chunk_size\n");
 
    my $callbacks = {
       init => sub {
@@ -10312,6 +10318,11 @@ sub main {
                   $tbl->{nibble_time}, # is this amount of time
                );
 
+               # Enforce minimum chunk size
+               $tbl->{chunk_size} = ($tbl->{chunk_size} < $min_chunk_size)
+                                  ? $min_chunk_size
+                                  : $tbl->{chunk_size};
+
                if ( $tbl->{chunk_size} < 1 ) {
                   # This shouldn't happen.  WeightedAvgRate::update() may
                   # return a value < 1, but minimum chunk size is 1.
@@ -13298,6 +13309,14 @@ them. The existing rows which contain NULL values will be converted to the defau
 based on datatype, e.g. 0 for number datatypes, '' for string datatypes.
 New rows will use the user defined default value if specified for the column.
 
+=item --dynamic-min-chunk-size
+
+type: int; default: 1
+
+When using dynamic chunk sizing, do not copy chunks smaller than this desired minimum chunk size.
+
+The minimum value for this option is 1 and default value is 1.
+
 =item --only-same-schema-fks
 
 Check foreigns keys only on tables on the same schema than the original table.

From dbbc4f1768fd3ddb63d0e8569bc7f0cb1fd62ae5 Mon Sep 17 00:00:00 2001
From: Ahir Reddy <ahirreddy@gmail.com>
Date: Thu, 22 Aug 2024 14:13:56 -0700
Subject: [PATCH 2/2] better comments

---
 bin/pt-online-schema-change | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/bin/pt-online-schema-change b/bin/pt-online-schema-change
index 0199070f0..7f0c9d271 100755
--- a/bin/pt-online-schema-change
+++ b/bin/pt-online-schema-change
@@ -10318,10 +10318,11 @@ sub main {
                   $tbl->{nibble_time}, # is this amount of time
                );
 
-               # Enforce minimum chunk size
-               $tbl->{chunk_size} = ($tbl->{chunk_size} < $min_chunk_size)
-                                  ? $min_chunk_size
-                                  : $tbl->{chunk_size};
+               # Enforce minimum chunk size. If the value is lower than the specified min, update
+               # the chunk size value accordingly.
+               if ($tbl->{chunk_size} < $min_chunk_size) {
+                  $tbl->{chunk_size} = $min_chunk_size;
+               }
 
                if ( $tbl->{chunk_size} < 1 ) {
                   # This shouldn't happen.  WeightedAvgRate::update() may