Convert field data type from text to Date

Elastic Stack Elasticsearch
7

PFB details

new index with the correct data type as below

   PUT /index-0002
   {
   "settings":{
      "number_of_shards":4,
      "number_of_replicas":1
   },
   "mappings":{
      "properties":{
         "filed1":{
            "type":"long"
         },
         "filed2":{
            "type":"text"
         },
         "filed3":{
            "type":"text"
         },
         "filed4":{
            "type":"text"
         },
         "timestamp":{
            "type":"date",
            "format":"yyyy-MM-dd HH:mm:ss.SSS"
         }
      }
   }
}

migrated data from old to new index using reindex API

 POST /_reindex
{
   "source":{
      "index":"index-0001"
   },
   "dest":{
      "index":"index-0002"
   }
}

index-0001 mapping

"mappings":{
   "properties":{
      "filed1":{
         "type":"text"
      },
      "filed2":{
         "type":"text"
      },
      "filed3":{
         "type":"text"
      },
      "filed4":{
         "type":"text"
      },
      "timestamp":{
         "type":"text"
      }
   }
}

Document Example

{
   "_index":"index-0001",
   "_type":"_doc",
   "_id":"rE64RXYBWfNr3RkH119n",
   "_version":1,
   "_seq_no":240,
   "_primary_term":1,
   "found":true,
   "_source":{
      "filed1":"7",
      "filed2":"info",
      "filed3":"Source exception",
      "filed4":"Exiting ",
      "timestamp":"2020-12-09 03:32:59.830"
   }
}