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Parquet-tool命令行使用

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To examine the internal structure and data of Parquet files, you can use the parquet-tools command that comes with CDH. Make sure this command is in your $PATH. (Typically, it is symlinked from /usr/bin; sometimes, depending on your installation setup, you might need to locate it under a CDH-specific bin directory.) The arguments to this command let you perform operations such as:

  • cat: 打印文件的全部内容信息到标准输出
  • head: 打印文件的头几行内容信息到标准输出
  • schema: 打印Parquet的schema
  • meta: 打印 file footer metadata, 包含 key-value properties (like Avro schema), compression ratios, encodings, compression used, and row group information.
  • dump: 打印所有数据和metadata.

如果没有将jar配置到环境变量，可以使用java -jar parquet-tools-1.8.2.jar -h

Use parquet-tools -h to see usage information for all the arguments. Here are some examples showing parquet-tools usage

cat 命令

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$ # Be careful doing this for a big file! Use parquet-tools head to be safe.
$ parquet-tools cat sample.parq
year = 1992
month = 1
day = 2
dayofweek = 4
dep_time = 748
crs_dep_time = 750
arr_time = 851
crs_arr_time = 846
carrier = US
flight_num = 53
actual_elapsed_time = 63
crs_elapsed_time = 56
arrdelay = 5
depdelay = -2
origin = CMH
dest = IND
distance = 182
cancelled = 0
diverted = 0

year = 1992
month = 1
day = 3
...

head 命令

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$ parquet-tools head -n 2 sample.parq
year = 1992
month = 1
day = 2
dayofweek = 4
dep_time = 748
crs_dep_time = 750
arr_time = 851
crs_arr_time = 846
carrier = US
flight_num = 53
actual_elapsed_time = 63
crs_elapsed_time = 56
arrdelay = 5
depdelay = -2
origin = CMH
dest = IND
distance = 182
cancelled = 0
diverted = 0

year = 1992
month = 1
day = 3
...

schema命令

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$ parquet-tools schema sample.parq
message schema {
optional int32 year;
optional int32 month;
optional int32 day;
optional int32 dayofweek;
optional int32 dep_time;
optional int32 crs_dep_time;
optional int32 arr_time;
optional int32 crs_arr_time;
optional binary carrier;
optional int32 flight_num;
...

meta 命令

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$ parquet-tools meta sample.parq
creator:             impala version 2.2.0-cdh5.4.3 (build 517bb0f71cd604a00369254ac6d88394df83e0f6)

file schema:         schema
-------------------------------------------------------------------
year:                OPTIONAL INT32 R:0 D:1
month:               OPTIONAL INT32 R:0 D:1
day:                 OPTIONAL INT32 R:0 D:1
dayofweek:           OPTIONAL INT32 R:0 D:1
dep_time:            OPTIONAL INT32 R:0 D:1
crs_dep_time:        OPTIONAL INT32 R:0 D:1
arr_time:            OPTIONAL INT32 R:0 D:1
crs_arr_time:        OPTIONAL INT32 R:0 D:1
carrier:             OPTIONAL BINARY R:0 D:1
flight_num:          OPTIONAL INT32 R:0 D:1
...

row group 1:         RC:20636601 TS:265103674
-------------------------------------------------------------------
year:                 INT32 SNAPPY DO:4 FPO:35 SZ:10103/49723/4.92 VC:20636601 ENC:PLAIN_DICTIONARY,RLE,PLAIN
month:                INT32 SNAPPY DO:10147 FPO:10210 SZ:11380/35732/3.14 VC:20636601 ENC:PLAIN_DICTIONARY,RLE,PLAIN
day:                  INT32 SNAPPY DO:21572 FPO:21714 SZ:3071658/9868452/3.21 VC:20636601 ENC:PLAIN_DICTIONARY,RLE,PLAIN
dayofweek:            INT32 SNAPPY DO:3093276 FPO:3093319 SZ:2274375/5941876/2.61 VC:20636601 ENC:PLAIN_DICTIONARY,RLE,PLAIN
dep_time:             INT32 SNAPPY DO:5367705 FPO:5373967 SZ:28281281/28573175/1.01 VC:20636601 ENC:PLAIN_DICTIONARY,RLE,PLAIN
crs_dep_time:         INT32 SNAPPY DO:33649039 FPO:33654262 SZ:10220839/11574964/1.13 VC:20636601 ENC:PLAIN_DICTIONARY,RLE,PLAIN
arr_time:             INT32 SNAPPY DO:43869935 FPO:43876489 SZ:28562410/28797767/1.01 VC:20636601 ENC:PLAIN_DICTIONARY,RLE,PLAIN
crs_arr_time:         INT32 SNAPPY DO:72432398 FPO:72438151 SZ:10908972/12164626/1.12 VC:20636601 ENC:PLAIN_DICTIONARY,RLE,PLAIN
carrier:              BINARY SNAPPY DO:83341427 FPO:83341558 SZ:114916/128611/1.12 VC:20636601 ENC:PLAIN_DICTIONARY,RLE,PLAIN
flight_num:           INT32 SNAPPY DO:83456393 FPO:83488603 SZ:10216514/11474301/1.12 VC:20636601 ENC:PLAIN_DICTIONARY,RLE,PLAIN
...

Meta Legend

Row Group Totals

Acronym Definition
RC Row Count
TS Total Byte Size

Row Group Column Details

Acronym Definition
DO Dictionary Page Offset
FPO First Data Page Offset
SZ:{x}/{y}/{z} Size in bytes. x = Compressed total, y = uncompressed total, z = y:x ratio
VC Value Count
RLE Run-Length Encoding