![]() If you want to utilize the partition feature, design the subfolder structure carefully, and always distribute the files among the subfolders at same level.If you don’t want to utilize partition feature, store all the files in the root folder.However, in order the Glue crawler to add the S3 files into the data catalog correctly, we have to follow the rules below to organize and plan the S3 folder structure.As long as the files have same format, the data from all the files can be accessed from the one single Redshift table or external table by specifying the S3 location as the root folder for the files, no matter where they are stored within the multi-level subfolders. Redshift “COPY” or external table don’t care about the S3 subfolder structure and how the files are organized within the root folder or its subfolders.The partitions are Conclusionsįrom the test results above, we can conclude: It has all the data from the 4 files, and it is partitioned on two coluumns. Glue Crawler Catalog Result: Discoveried one table: "test" (the root-folder name). Case 5: Files are in the same level of multi-level subfolders: ![]() "sbf2" - It has the data from the two files: "file3" and "file4". it is partitioned into two partitions "sbsbf11", and "sbsbf12". Glue Crawler Catalog Result: Discoveried two tables: "sbf1" - It has the data from the two files: "file1" and "file2". Case 4: Files are in the different level of the multi-level subfolders: It has all the data from the 4 files, and it is partitioned on one coluumn into two partitions "sbf1", and "sbf2" (sub-folder names become partition values). Case 3: Files are in the same level subfolders: Glue Crawler Catalog Result: Discoveried four tables: (the sub-folder name and file names) "sbf1" - Only has the data from "file1". ![]() Case 2: Some files are in the root folder and some files in subfolders: It has all the data from the 4 files, and it is not partitioned. Redshift Result: Both the tables "test_csv" and "test_csv_ext" have all the data from the 4 files.
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