README.md in embulk-output-redshift-0.8.0 vs README.md in embulk-output-redshift-0.8.1

@@ -17,15 +17,15 @@
 - **password**: database login password (string, default: "")
 - **database**: destination database name (string, required)
 - **schema**: destination schema name (string, default: "public")
 - **temp_schema**: schema name for intermediate tables. by default, intermediate tables will be created in the schema specified by `schema`. replace mode doesn't support temp_schema. (string, optional)
 - **table**: destination table name (string, required)
-- **create_table_constraint** table constraint added to `CREATE TABLE` statement, like `CREATE TABLE <table_name> (<column1> <type1>, <column2> <type2>, ..., <create_table_constraint>) <create_table_option>`.
-- **create_table_option** table option added to `CREATE TABLE` statement, like `CREATE TABLE <table_name> (<column1> <type1>, <column2> <type2>, ..., <create_table_constraint>) <create_table_option>`.
+- **create_table_constraint**: table constraint added to `CREATE TABLE` statement, like `CREATE TABLE <table_name> (<column1> <type1>, <column2> <type2>, ..., <create_table_constraint>) <create_table_option>`.
+- **create_table_option**: table option added to `CREATE TABLE` statement, like `CREATE TABLE <table_name> (<column1> <type1>, <column2> <type2>, ..., <create_table_constraint>) <create_table_option>`.
 - **access_key_id**: deprecated. `aws_access_key_id` should be used (see "basic" in `aws_auth_method`).
 - **secret_access_key**: deprecated. `aws_secret_access_key` should be used (see "basic" in `aws_auth_method`).
-- **aws_auth_method**: name of mechanism to authenticate requests ("basic", "env", "instance", "profile", "properties", "anonymous", or "session". default: "basic")
+- **aws_auth_method**: name of mechanism to authenticate requests ("basic", "env", "instance", "profile", "properties", "anonymous", "session" or "default". default: "basic")
 
   - "basic": uses `access_key_id` and `secret_access_key` to authenticate.
 
     - **aws_access_key_id**: AWS access key ID (string, required)
 
@@ -60,17 +60,24 @@
 
     - **aws_secret_access_key**: AWS secret access key (string, required)
 
     - **aws_session_token**: session token (string, required)
 
+  - "default": uses AWS SDK's default strategy to look up available credentials from runtime environment. This method behaves like the combination of the following methods.
+
+    1. "env"
+    1. "properties"
+    1. "profile"
+    1. "instance"
+
 - **iam_user_name**: IAM user name for uploading temporary files to S3. The user should have permissions of `s3:GetObject`, `s3:PutObject`, `s3:DeleteObject`, `s3:ListBucket` and `sts:GetFederationToken`. And furthermore, the user should have permission of `s3:GetBucketLocation` if Redshift region and S3 bucket region are different. (string, default: "", but we strongly recommend that you use IAM user for security reasons. see below.)
 - **s3_bucket**: S3 bucket name for temporary files
 - **s3_key_prefix**: S3 key prefix for temporary files (string, default: "")
 - **delete_s3_temp_file**: whether to delete temporary files uploaded on S3 (boolean, default: true)
 - **options**: extra connection properties (hash, default: {})
-- **retry_limit** max retry count for database operations (integer, default: 12)
-- **retry_wait** initial retry wait time in milliseconds (integer, default: 1000 (1 second))
-- **max_retry_wait** upper limit of retry wait, which will be doubled at every retry (integer, default: 1800000 (30 minutes))
+- **retry_limit**: max retry count for database operations (integer, default: 12)
+- **retry_wait**: initial retry wait time in milliseconds (integer, default: 1000 (1 second))
+- **max_retry_wait**: upper limit of retry wait, which will be doubled at every retry (integer, default: 1800000 (30 minutes))
 - **mode**: "insert", "insert_direct", "truncate_insert", "replace" or "merge". See below. (string, required)
 - **merge_keys**: key column names for merging records in merge mode (string array, required in merge mode)
 - **batch_size**: size of a single batch insert (integer, default: 16777216)
 - **default_timezone**: If input column type (embulk type) is timestamp, this plugin needs to format the timestamp into a SQL string. This default_timezone option is used to control the timezone. You can overwrite timezone for each columns using column_options option. (string, default: `UTC`)
 - **column_options**: advanced: a key-value pairs where key is a column name and value is options for the column.