HBase DATA-SCIENCE-OPTIMIZE Practice Questions (Page 6)

Questions 26–28

1. 26foundation · easy

   What is the role of the Write-Ahead Log (WAL) in HBase?

   • AIt stores data in memory for fast reads.
   • BIt provides durability by logging changes before they are applied to MemStore.
   • CIt compacts HFiles to improve read performance.
   • DIt caches frequently accessed data in memory.
   Reveal Solution Discussion Select an answer first
2. 27foundation · easy

   Which of the following best describes a cell in HBase?

   • AA collection of rows that share the same row key.
   • BA metadata entry that tracks the schema of a table.
   • CA logical grouping of columns that are stored together.
   • DA single value stored at the intersection of a row and a column, with a timestamp.
   Reveal Solution Discussion Select an answer first
3. 28application · medium

   An HBase cluster is experiencing slow write performance. The operations team notices that RegionServers are frequently flushing MemStores to HFiles. Which configuration change is most likely to improve write throughput?

   • ADisable the Write-Ahead Log (WAL)
   • BIncrease the number of ZooKeeper nodes
   • CIncrease the MemStore flush size
   • DReduce the number of column families
   Reveal Solution Discussion Select an answer first