Posts

Showing posts with the label Oracle 12c

Featured Post

8 Ways to Optimize AWS Glue Jobs in a Nutshell

-
Image
  Improving the performance of AWS Glue jobs involves several strategies that target different aspects of the ETL (Extract, Transform, Load) process. Here are some key practices. 1. Optimize Job Scripts Partitioning : Ensure your data is properly partitioned. Partitioning divides your data into manageable chunks, allowing parallel processing and reducing the amount of data scanned. Filtering : Apply pushdown predicates to filter data early in the ETL process, reducing the amount of data processed downstream. Compression : Use compressed file formats (e.g., Parquet, ORC) for your data sources and sinks. These formats not only reduce storage costs but also improve I/O performance. Optimize Transformations : Minimize the number of transformations and actions in your script. Combine transformations where possible and use DataFrame APIs which are optimized for performance. 2. Use Appropriate Data Formats Parquet and ORC : These columnar formats are efficient for storage and querying, signif
Post a Comment
Read more

Oracle 12C 'Bitmap Index' benefits over B-tree Index

-
Image
#Oracle 12C 'Bitmap Index' benefits over B-tree Index: A bitmap index has a significantly different structure from a B-tree index in the leaf node of the index. It stores one string of bits for each possible value (the cardinality) of the column being indexed. Note: One string of BITs means -Each tupple of possible value it assigns '1' bit in a string.So, all the BITs become a string ( This is an example, on which column you created BIT map index) The length of the string of bits is the same as the number of rows in the table being indexed. In addition to saving a tremendous amount of space compared to traditional indexes, a bitmap index can provide dramatic improvements in response time because Oracle can quickly remove potential rows from a query containing multiple WHERE clauses long before the table itself needs to be accessed. Multiple bitmaps can use logical AND and OR operations to determine which rows to access from the table. Although you ca
Post a Comment
Read more