README.md in embulk-input-mysql-0.2.1 vs README.md in embulk-input-mysql-0.2.2

@@ -15,10 +15,19 @@
 - **password**: database login password (string, default: "")
 - **database**: destination database name (string, required)
 - **table**: destination name (string, required)
 - **select**: comma-separated list of columns to select (string, default: "*")
 - **where**: WHERE condition to filter the rows (string, default: no-condition)
-- **fetch_rows**: number of rows to fetch one time (used for java.sql.Statement#setFetchSize) (integer, default: 10000)
+- **fetch_rows**: number of rows to fetch one time (integer, default: 10000)
+  - If this value is set to > 1:
+    - It uses a server-side prepared statement and fetches rows by chunks.
+    - Internally, `useCursorFetch=true` is enabled and `java.sql.Statement.setFetchSize` is set to the configured value.
+  - If this value is set to 1:
+    - It uses a client-side built statement and fetches rows one by one.
+    - Internally, `useCursorFetch=false` is used and `java.sql.Statement.setFetchSize` is set to Integer.MIN_VALUE.
+  - If this value is set to -1:
+    - It uses a client-side built statement and fetches all rows at once. This may cause OutOfMemoryError.
+    - Internally, `useCursorFetch=false` is used and `java.sql.Statement.setFetchSize` is not set.
 - **options**: extra JDBC properties (hash, default: {})
 
 ## Example
 
 ```yaml