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[1] https://blogs.oracle.com/dbstorage/compressing-your-indexes:-index-key-compression-part-1
[2] https://blogs.oracle.com/dbstorage/compressing-your-indexes:-advanced-index-compression-part-2
[3] https://docs.mongodb.com/manual/core/wiredtiger/#storage-wiredtiger-compression
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[1] http://man7.org/linux/man-pages/man2/fallocate.2.html
[2] https://mariadb.org/innodb-holepunch-compression-vs-the-filesystem-in-mariadb-10-1/
[3] https://dev.mysql.com/doc/refman/5.7/en/innodb-compression-background.html
[4] https://mysqlserverteam.com/innodb-transparent-page-compression/
[5] https://www.objectrocket.com/blog/company/mongodb-3-0-wiredtiger-compression-and-performance/
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