AWS Datapipeline : moving data from RDS database(postgres) to Redshift using pipeline - amazon-web-services

Question

Basically i am trying to transfer data from postgres to redshift using aws datapipeline and the process i am following
Write a pipeline(CopyActivity) that moves data from postgres to s3
Write a pipeline(RedShiftCopyActivity) that moves data from s3 to redshift
So in my case both are working perfectly with the pipelines i wrote, but the problem is the data was duplicating in the Redshift database
For example below is the data from postgres database in a table called company
After the successful run of s3 to redshift(RedShiftCopyActivity) pipeline the data was copied but it was duplicated as below
below is the some of the definition part from RedShiftCopyActivity(S3 to Redshift) pipeline
pipeline_definition = [{
"id":"redshift_database_instance_output",
"name":"redshift_database_instance_output",
"fields":[
{
"key" : "database",
"refValue" : "RedshiftDatabaseId_S34X5",
},
{
"key" : "primaryKeys",
"stringValue" : "id",
},
{
"key" : "type",
"stringValue" : "RedshiftDataNode",
},
{
"key" : "tableName",
"stringValue" : "company",
},
{
"key" : "schedule",
"refValue" : "DefaultScheduleTime",
},
{
"key" : "schemaName",
"stringValue" : RedShiftSchemaName,
},
]
},
{
"id":"CopyS3ToRedshift",
"name":"CopyS3ToRedshift",
"fields":[
{
"key" : "output",
"refValue" : "redshift_database_instance_output",
},
{
"key" : "input",
"refValue" : "s3_input_data",
},
{
"key" : "runsOn",
"refValue" : "ResourceId_z9RNH",
},
{
"key" : "type",
"stringValue" : "RedshiftCopyActivity",
},
{
"key" : "insertMode",
"stringValue" : "KEEP_EXISTING",
},
{
"key" : "schedule",
"refValue" : "DefaultScheduleTime",
},
]
},]
So according to the docs of RedShitCopyActivity we need to use insertMode to describe how the data should behave(inserted/updated/deleted) when copying to database table as below
insertMode : Determines what AWS Data Pipeline does with pre-existing data in the target table that overlaps with rows in the data to be loaded. Valid values are KEEP_EXISTING, OVERWRITE_EXISTING, TRUNCATE and APPEND. KEEP_EXISTING adds new rows to the table, while leaving any existing rows unmodified. KEEP_EXISTING and OVERWRITE_EXISTING use the primary key, sort, and distribution keys to identify which incoming rows to match with existing rows, according to the information provided in Updating and inserting new data in the Amazon Redshift Database Developer Guide. TRUNCATE deletes all the data in the destination table before writing the new data. APPEND will add all records to the end of the Redshift table. APPEND does not require a primary, distribution key, or sort key so items that may be potential duplicates may be appended.
So what my requirements are
When copying from postgres (infact data is in s3 now) to Redshift database if it found already existing rows then just update it
If it founds new records from s3 then create new records in Redshift
But for me even though i have used KEEP_EXISTING or OVERWRITE_EXISTING, the data was just repeating over and over again as shown in the above redshift database picture
So finally how to achieve my requirements ? are there still any tweaks or settings to add to my configuration ?
Edit
Table(company) definition from redshift

Answer 1

If you want to avoid duplication , you must define Primary key in redshift and also set myInsertMode as "OVERWRITE_EXISTING" .