[CASSANDRA-5766] The output of the describe command does not necessarily give you the right DDL to re-create the CF

• Type: Bug
• Status: Resolved
• Priority: Normal
• Resolution: Fixed
• Fix Version/s: 1.2.7
• Component/s: Legacy/Tools
• Labels: cqlsh describe
• Severity: Normal
• Assignee: Aleksey Yeschenko
• Reporter: Steven Lowenthal

Authors

Aleksey Yeschenko

Reviewers

Brandon Williams

• Created: 16/Jul/13 22:08
• Updated: 16/Apr/19 09:32
• Resolved: 18/Jul/13 20:44

Description

If compression is not set for a CF, cqlsh omits the compression attribute. When you replay that very same DDL, you get a CF with Snappy compression. This may occur with other parameters. Perhaps describe should always show every parameter in full. The absence of a setting is a setting. (Think of the arrow in the FedEx logo).

Create a CF with cassandra-stress. cassandra-stress defaults to NO compression.

~/dse/resources/cassandra/tools/bin/cassandra-stress -S 100 -c 1 --num-keys 1

describe it
CREATE TABLE "Standard1" (
key blob PRIMARY KEY,
"C0" blob
) WITH COMPACT STORAGE AND
bloom_filter_fp_chance=0.010000 AND
caching='KEYS_ONLY' AND
comment='' AND
dclocal_read_repair_chance=0.000000 AND
gc_grace_seconds=864000 AND
read_repair_chance=0.100000 AND
replicate_on_write='true' AND
populate_io_cache_on_flush='false' AND
compaction=

{'class': 'SizeTieredCompactionStrategy'}

;

replay it - I changed the cf name to standard2

describe the new CF:

CREATE TABLE standard2 (
key blob PRIMARY KEY,
"C0" blob
) WITH COMPACT STORAGE AND
bloom_filter_fp_chance=0.010000 AND
caching='KEYS_ONLY' AND
comment='' AND
dclocal_read_repair_chance=0.000000 AND
gc_grace_seconds=864000 AND
read_repair_chance=0.100000 AND
replicate_on_write='true' AND
populate_io_cache_on_flush='false' AND
compaction=

{'class': 'SizeTieredCompactionStrategy'}

AND
compression=

{'sstable_compression': 'SnappyCompressor'}

;