README.md in embulk-output-redshift-0.8.2 vs README.md in embulk-output-redshift-0.8.3

@@ -19,10 +19,11 @@
 - **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>`.
+- **transaction_isolation**: transaction isolation level for each connection ("read_uncommitted", "read_committed", "repeatable_read" or "serializable"). if not specified, database default value will be used.
 - **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", "session" or "default". default: "basic")
 
   - "basic": uses `access_key_id` and `secret_access_key` to authenticate.
@@ -72,10 +73,10 @@
 - **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_limit**: max retry count for database operations (integer, default: 12). When intermediate table to create already created by another process, this plugin will retry with another table name to avoid collision.
 - **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)