diff --git a/docs/how-delta-lake-works/architecture-of-delta-table.md b/docs/how-delta-lake-works/architecture-of-delta-table.md index 25996878ec..5a6df49969 100644 --- a/docs/how-delta-lake-works/architecture-of-delta-table.md +++ b/docs/how-delta-lake-works/architecture-of-delta-table.md @@ -27,7 +27,7 @@ tmp/some-table └── 00000000000000000000.json ``` -The Parquet file stores the data that was written. The `_delta_log` directory stores metadata about the transactions. Let's inspect the `_delta_log/00000000000000000000.json` file. +The Parquet file stores the data that was written. The `_delta_log` directory stores metadata about the transactions. Let's inspect the `_delta_log/00000000000000000000.json` file. ```json { @@ -78,9 +78,9 @@ The Parquet file stores the data that was written. The `_delta_log` directory s The transaction log file contains the following information: -* the files added to the Delta table -* schema of the files -* column level metadata including the min/max value for each file +- the files added to the Delta table +- schema of the files +- column level metadata including the min/max value for each file Create another pandas DataFrame and append it to the Delta table to see how this transaction is recorded. @@ -194,11 +194,11 @@ Here are the contents of the `_delta_log/0002.json` file: } ``` -This transaction adds a data file and marks the two exising data files for removal. Marking a file for removal in the transaction log is known as "tombstoning the file" or a "logical delete". This is different from a "physical delete" which actually removes the data file from storage. +This transaction adds a data file and marks the two exising data files for removal. Marking a file for removal in the transaction log is known as "tombstoning the file" or a "logical delete". This is different from a "physical delete" which actually removes the data file from storage. ## How Delta table operations differ from data lakes -Data lakes consist of data files persisted in storage. They don't have a transaction log that retain metadata about the transactions. +Data lakes consist of data files persisted in storage. They don't have a transaction log that retain metadata about the transactions. Data lakes perform transactions differently than Delta tables. @@ -206,6 +206,6 @@ When you perform an overwrite tranasction with a Delta table, you logically dele Data lakes don't support logical deletes, so you have to physically delete the data from storage. -Logical data operations are safer because they can be rolled back if they don't complete successfully. Physically removing data from storage can be dangerous, especially if it's before a transaction is complete. +Logical data operations are safer because they can be rolled back if they don't complete successfully. Physically removing data from storage can be dangerous, especially if it's before a transaction is complete. -We're now ready to look into Delta Lake ACID transactions in more detail. +We're now ready to look into [Delta Lake ACID transactions](../how-delta-lake-works/delta-lake-acid-transactions.md) in more detail.