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--- mysql:error_1071 [2016/07/01 23:13] – peter
+++ mysql:error_1071 [2020/07/15 09:30] (current) – external edit 127.0.0.1
@@ Line 8: / Line 8: @@
 Thus, you need to multiply your key field's character limit by, 1, 3, or 4 (depending on which character set is being used) to determine the number of bytes the key field will actually try to use.
-  * For **uft8** a maximum of 255 characters can therefore be used for InnoDB key field because 767/3≈255.
+  * For **uft8** a maximum of 255 characters can therefore be used for an InnoDB key field because 767/3≈255.
-  * For **uft8mb4** a maximum of 191 characters can therefore be used for InnoDB key field because 767/4≈191.
+  * For **uft8mb4** a maximum of 191 characters can therefore be used for an InnoDB key field because 767/4≈191.
 There is also a separate 3072 byte limit per index.  The 767 byte limit is per column, so you can include multiple columns (each 767 bytes or smaller) up to 3072 total bytes per index, but no column longer than 767 bytes.  (MyISAM is a little different.  It has a 1000 byte index length limit, but no separate column length limit within that).
-One workaround for these limits is to only index a prefix, for example, here only the 191 characters from column1 is part of the index:
+One workaround for these limits is to only index part of a field, for example, here only 191 characters from column1 is part of the index:
 <code mysql>
@@ Line 26: / Line 26: @@
 <code>
-The InnoDB internal maximum key length is 3500 bytes, but MySQL itself restricts this to 3072 bytes.  This limit applies to the length of the combined index key in a multi-column index.
+The InnoDB internal maximum key length is 3500 bytes, but MySQL itself restricts this to 3072 bytes.
+This limit applies to the length of the combined index key in a multi-column index.
 </code>
-Read on for details and examples about **innodb_large_prefix**.
+===== Using innodb_large_prefix =====
 Here are a few pre-requisites for using **innodb_large_prefix**:
@@ Line 38: / Line 40: @@
 The default file format is still Antelope for backwards compatibility, and the default row format is COMPACT.
-You can set both **innodb_file_format** and **innodb_large_prefix** dynamically, but you should also set them in my.cnf so they survive a restart.
+You can set both **innodb_file_format** and **innodb_large_prefix** dynamically, but you should also set them in **my.cnf** so they survive a restart.
 Here’s an example.  If I try to create this table with **innodb_large_prefix** disabled I get an error: