+threadskv2.c Multi-Threaded/Multi-Process based on threadskv1 that replaces the linear sorted key array with a red/black tree.
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+threadskv3.c Multi-Threaded/Multi-Process based on threadskv1 that introduces librarian filler slots in the linear key array to minimize data movement when a new key is inserted into the middle of the array.
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+threadskv4b.c Multi-Threaded/Multi-Process based on threadskv3 that manages duplicate keys added to the btree.
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+threadskv5.c Multi-Threaded/Multi-Process based on threadskv4b that supports bi-directional cursors through the btree. Also supports raw disk partitions for btrees.
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+threadskv6.c Multi-Threaded/Single-Process with traditional buffer pool manager using the swap device. Based on threadskv5 and btree2u.
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+threadskv7.c Multi-Threaded/Single-Process with atomic add of a set of keys under eventual consistency. Adds a lock manager.
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