COPY FROM

COPY ... FROM is a statement that allows loading data from files on the filesystem and importing them into SQreamDB tables. This is the recommended way for bulk loading CSV files into SQreamDB. In general, COPY moves data between filesystem files and SQreamDB tables.

Note

• Learn how to migrate from CSV files in the CSV guide

• To copy data from a table to a file, see COPY TO.

• To load Parquet or ORC files, see CREATE FOREIGN TABLE

Permissions

The role must have the INSERT permission to the destination table.

Syntax

 COPY [schema name.]table_name [ (<column_name>) [, ...] ]
   FROM WRAPPER fdw_name
   OPTIONS
   (
     [ copy_from_option [, ...] ]
   )


 schema_name ::= identifer

 table_name ::= identifier

 copy_from_option ::=

    LOCATION = { filename | S3 URI | HDFS URI }

    | QUOTE = {'C' | E'\ooo')

    | OFFSET = { offset }

    | LIMIT = { limit }

    | DELIMITER = '{ delimiter }'

    | RECORD_DELIMITER = '{ record delimiter }'

    | ERROR_LOG = '{ local filepath }'

    | REJECTED_DATA = '{ local filepath }'

    | CONTINUE_ON_ERROR = { true | false }

    | ERROR_COUNT = '{ error count }'

    | DATETIME_FORMAT = '{ parser format }'

    | AWS_ID = '{ AWS ID }'

    | AWS_SECRET = '{ AWS Secret }'

offset ::= positive integer

limit ::= positive integer

delimiter ::= string

record delimiter ::= string

error count ::= integer

parser_format ::= see supported parser table below

AWS ID ::= string

AWS Secret ::= string

Note

Some options are applicable to CSVs only.

These include: OFFSET, LIMIT, DELIMITER, RECORD_DELIMITER, REJECTED_DATA, DATETIME_FORMAT

Elements

Parameter	Default value	Value range	Description
[schema_name.]table_name	None		Table to copy data into
QUOTE	"		Specifies an alternative quote character. The quote character must be a single, 1-byte printable ASCII character, and the equivalent octal syntax of the copy command can be used. The quote character cannot be contained in the field delimiter, the record delimiter, or the null marker. QUOTE can be used with csv_fdw in COPY FROM and foreign tables. The following characters cannot be an alternative quote character: "-.:\\0123456789abcdefghijklmnopqrstuvwxyzN"
fdw_name		csv_fdw, orc_fdw, parquet_fdw, json_fdw, or avro_fdw	The name of the Foreign Data Wrapper to use
LOCATION	None		A path on the local filesystem, S3, or HDFS URI. For example, /tmp/foo.csv, s3://my-bucket/foo.csv, or hdfs://my-namenode:8020/foo.csv. The local path must be an absolute path that SQream DB can access. Wildcards are premitted in this field.
OFFSET	1	>1, but no more than the number of lines in the first file	The row number to start with. The first row is 1.
LIMIT	unlimited	1 to 2147483647.	When specified, tells SQream DB to stop loading after the specified number of rows. Unlimited if unset.
DELIMITER	','	Almost any ASCII character, See field delimiters section below	Specifies the field terminator - the character (or characters) that separates fields or columns within each row of the file.
RECORD_DELIMITER	\n (UNIX style newline)	\n, \r\n, \r	Specifies the row terminator - the character that separates lines or rows, also known as a new line separator.
ERROR_LOG	No error log		When used, the COPY process will write error information from unparsable rows to the file specified by this parameter. ERROR_LOG requires CONTINUE_ON_ERROR to be set to true If an existing file path is specified, it will be overwritten. Specifying the same file for ERROR_LOG and REJECTED_DATA is not allowed and will result in error. Specifing an error log when creating a foreign table will write a new error log for every query on the foreign table.
REJECTED_DATA	Inactive		When used, the COPY process will write the rejected record lines to this file. If an existing file path is specified, it will be overwritten. Specifying the same file for ERROR_LOG and REJECTED_DATA is not allowed and will result in error. Specifing an error log when creating a foreign table will write a new error log for every query on the foreign table.
CONTINUE_ON_ERROR	false	true, false	Specifies if errors should be ignored or skipped. When set to true, the transaction will continue despite rejected data. This parameter should be set together with ERROR_COUNT When reading multiple files, if an entire file can’t be opened it will be skipped.
ERROR_COUNT	unlimited	1 to 2147483647	Specifies the threshold for the maximum number of faulty records that will be ignored. This setting must be used in conjunction with CONTINUE_ON_ERROR.
DATETIME_FORMAT	ISO8601 for all columns	See table below	Allows specifying a non-default date formats for specific columns
AWS_ID, AWS_SECRET	None		Specifies the authentication details for secured S3 buckets

Supported Date Formats

Supported date parsers

Name	Pattern	Examples
ISO8601, DEFAULT	YYYY-MM-DD [hh:mm:ss[.SSS]]	2017-12-31 11:12:13.456, 2018-11-02 11:05:00, 2019-04-04
ISO8601C	YYYY-MM-DD [hh:mm:ss[:SSS]]	2017-12-31 11:12:13:456
DMY	DD/MM/YYYY [hh:mm:ss[.SSS]]	31/12/2017 11:12:13.123
YMD	YYYY/MM/DD [hh:mm:ss[.SSS]]	2017/12/31 11:12:13.678
MDY	MM/DD/YYYY [hh:mm:ss[.SSS]]	12/31/2017 11:12:13.456
YYYYMMDD	YYYYMMDD[hh[mm[ss[SSS]]]]	20171231111213456
YYYY-M-D	YYYY-M-D[ h:m[:s[.S]]]	2017-9-10 10:7:21.1 (optional leading zeroes)
YYYY/M/D	YYYY/M/D[ h:m[:s[.S]]]	2017/9/10 10:7:21.1 (optional leading zeroes)
DD-mon-YYYY	DD-mon-YYYY[ hh:mm[:ss[.SSS]]]	31-Dec-2017 11:12:13.456
YYYY-mon-DD	YYYY-mon-DD[ hh:mm[:ss[.SSS]]]	2017-Dec-31 11:12:13.456

Pattern	Description
YYYY	four digit year representation (0000-9999)
MM	two digit month representation (01-12)
DD	two digit day of month representation (01-31)
m	short month representation (Jan-Dec)
a	short day of week representation (Sun-Sat).
hh	two digit 24 hour representation (00-23)
h	two digit 12 hour representation (00-12)
P	uppercase AM/PM representation
mm	two digit minute representation (00-59)
ss	two digit seconds representation (00-59)
SSS	3 digits fraction representation for milliseconds (000-999)

Note

These date patterns are not the same as date parts used in the DATEPART function.

Supported Field Delimiters

Field delimiters can be one or more characters.

Customizing Quotations Using Alternative Characters

Syntax:

COPY t FROM wrapper csv_fdw OPTIONS (location = '/tmp/source_file.csv', quote='@');
COPY t TO wrapper csv_fdw OPTIONS (location = '/tmp/destination_file.csv', quote='@');

Example:

The following is an example of line taken from a CSV when customizing quotations using a character:

Pepsi-"Cola",@Coca-"Cola"@,Sprite,Fanta

Customizing Quotations Using ASCII Character Codes

Syntax:

copy t from wrapper csv_fdw options (location = '/tmp/source_file.csv', quote=E'\064');
copy t to wrapper csv_fdw options (location = '/tmp/destination_file.csv', quote=E'\064');

Example:

The following is an example of line taken from a CSV when customizing quotations using an ASCII character code:

Pepsi-"Cola",@Coca-"Cola"@,Sprite,Fanta

Multi-Character Delimiters

SQreamDB supports multi-character field delimiters, sometimes found in non-standard files.

A multi-character delimiter can be specified. For example, DELIMITER '%%', DELIMITER '{~}', etc.

Printable Characters

All printable ASCII character (except for N) can be used as a delimiter without special syntax. The default CSV field delimiter is a comma (,).

The following table shows the supported printable ASCII characters:

Character	Description	ASCII	Octal	Hex	Binary	HTML Code	HTML Name
(Space)	Space	32	40	20	100000	 
!	Exclamation Mark	33	41	21	100001	!	!
#	Hash or Number	35	43	23	100011	#	#
$	Dollar Sign	36	44	24	100100	$	$
%	Percentage	37	45	25	100101	%	%
&	Ampersand	38	46	26	100110	&	&
(	Left Parenthesis	40	50	28	101000	(	(
)	Right Parenthesis	41	51	29	101001	)	)
*	Asterisk	42	52	2A	101010	*	*
+	Plus Sign	43	53	2B	101011	+	+
,	Comma	44	54	2C	101100	,	,
/	Slash	47	57	2F	101111	/	/
;	Semicolon	59	73	3B	111011	&#59;	;
<	Less Than	60	74	3C	111100	&#60;	&lt;
=	Equals Sign	61	75	3D	111101	&#61;	&equals;
>	Greater Than	62	76	3E	111110	&#62;	&gt;
?	Question Mark	63	77	3F	111111	&#63;	&quest;
@	At Sign	64	100	40	1000000	&#64;	&commat;
[	Left Square Bracket	91	133	5B	1011011	&#91;	&lsqb;
\	Backslash	92	134	5C	1011100	&#92;	&bsol;
]	Right Square Bracket	93	135	5D	1011101	&#93;	&rsqb;
^	Caret or Circumflex	94	136	5E	1011110	&#94;	&hat;
_	Underscore	95	137	5F	1011111	&#95;	&lowbar;
`	Grave Accent	96	140	60	1100000	`	&grave;
{	Left Curly Bracket	123	173	7B	1111011	&#123;	&lcub;
|	Vertical Bar	124	174	7C	1111100	&#124;	&verbar;
}	Right Curly Bracket	125	175	7D	1111101	&#125;	&rcub;
~	Tilde	126	176	7E	1111110	&#126;	&tilde;
58	:	Colon	72	3A	111010	&#58;	&colon;
65	A	A	101	41	1000001	&#65;
66	B	B	102	42	1000010	&#66;
67	C	C	103	43	1000011	&#67;
68	D	D	104	44	1000100	&#68;
69	E	E	105	45	1000101	&#69;
70	F	F	106	46	1000110	&#70;
71	G	G	107	47	1000111	&#71;
72	H	H	110	48	1001000	&#72;
73	I	I	111	49	1001001	&#73;
74	J	J	112	4A	1001010	&#74;
75	K	K	113	4B	1001011	&#75;
76	L	L	114	4C	1001100	&#76;
77	M	M	115	4D	1001101	&#77;
79	O	O	117	4F	1001111	&#79;
80	P	P	120	50	1010000	&#80;
81	Q	Q	121	51	1010001	&#81;
82	R	R	122	52	1010010	&#82;
83	S	S	123	53	1010011	&#83;
84	T	T	124	54	1010100	&#84;
85	U	U	125	55	1010101	&#85;
86	V	V	126	56	1010110	&#86;
87	W	W	127	57	1010111	&#87;
88	X	X	130	58	1011000	&#88;
89	Y	Y	131	59	1011001	&#89;
90	Z	Z	132	5A	1011010	&#90;
92	\	Backslash	134	5C	01011100	&#92;
97	a	a	141	61	1100001	&#97;
98	b	b	142	62	1100010	&#98;
99	c	c	143	63	1100011	&#99;
100	d	d	144	64	1100100	&#100;
101	e	e	145	65	1100101	&#101;
102	f	f	146	66	1100110	&#102;
103	g	g	147	67	1100111	&#103;
104	h	h	150	68	1101000	&#104;
105	i	i	151	69	1101001	&#105;
106	j	j	152	6A	1101010	&#106;
107	k	k	153	6B	1101011	&#107;
108	l	l	154	6C	1101100	&#108;
109	m	m	155	6D	1101101	&#109;
110	n	n	156	6E	1101110	&#110;
111	o	o	157	6F	1101111	&#111;
112	p	p	160	70	1110000	&#112;
113	q	q	161	71	1110001	&#113;
114	r	r	162	72	1110010	&#114;
115	s	s	163	73	1110011	&#115;
116	t	t	164	74	1110100	&#116;
117	u	u	165	75	1110101	&#117;
118	v	v	166	76	1110110	&#118;
119	w	w	167	77	1110111	&#119;
120	x	x	170	78	1111000	&#120;
121	y	y	171	79	1111001	&#121;
122	z	z	172	7A	1111010	&#122;

Non-Printable Characters

A tab can be specified by escaping it, for example \t. Other non-printable characters can be specified using their octal representations, by using the E'\000' format, where 000 is the octal value of the character.

For example, ASCII character 15, known as “shift in”, can be specified using E'\017'.

The following table shows the supported non-printable ASCII characters:

Character	Description	Octal	ASCII	Hex	Binary	HTML Code	HTML Name
NUL	Null	0	0	0	0	�
SOH	Start of Heading	1	1	1	1	
STX	Start of Text	2	2	2	10	
ETX	End of Text	3	3	3	11	
EOT	End of Transmission	4	4	4	100	
ENQ	Enquiry	5	5	5	101	
ACK	Acknowledge	6	6	6	110	
BEL	Bell	7	7	7	111	
BS	Backspace	10	8	8	1000	
HT	Horizontal Tab	11	9	9	1001		
VT	Vertical Tab	13	11	0B	1011	
FF	NP Form Feed, New Page	14	12	0C	1100	
SO	Shift Out	16	14	0E	1110	
SI	Shift In	17	15	0F	1111	
DLE	Data Link Escape	20	16	10	10000	
DC1	Device Control 1	21	17	11	10001	
DC2	Device Control 2	22	18	12	10010	
DC3	Device Control 3	23	19	13	10011	
DC4	Device Control 4	24	20	14	10100	
NAK	Negative Acknowledge	25	21	15	10101	
SYN	Synchronous Idle	26	22	16	10110	
ETB	End of Transmission Block	27	23	17	10111	
CAN	Cancel	30	24	18	11000	
EM	End of Medium	31	25	19	11001	
SUB	Substitute	32	26	1A	11010	
ESC	Escape	33	27	1B	11011	
FS	File Separator	34	28	1C	11100	
GS	Group Separator	35	29	1D	11101	
RS	Record Separator	36	30	1E	11110	
US	Unit Separator	37	31	1F	11111	
DEL	Delete	177	127	7F	1111111	

Unsupported Field Delimiters

The following ASCII field delimiters (octal range 001 - 176) are not supported:

The following table shows the unsupported ASCII field delimiters:

ASCII	Character	Description	Octal	Hex	Binary	HTML Code	HTML Name
10	LF	NL Line Feed, New Line	12	0A	1010	

13	CR	Carriage Return	15	0D	1101	
34	“	Double Quote	42	22	100010	"	"
45	-	Minus Sign	55	2D	101101	-	−
46	.	Period	56	2E	101110	.	.
48	0	Zero	60	30	110000	0
49	1	Number One	61	31	110001	1
50	2	Number Two	62	32	110010	2
51	3	Number Three	63	33	110011	3
52	4	Number Four	64	34	110100	4
53	5	Number Five	65	35	110101	5
54	6	Number Six	66	36	110110	6
55	7	Number Seven	67	37	110111	7
56	8	Number Eight	70	38	111000	8
57	9	Number Nine	71	39	111001	9
58	:	Colon	72	3A	111010	:	:
92	\	Backslash	134	5C	01011100	\
78	N	N	116	4E	1001110	N

Capturing Rejected Rows

Prior to the column process and storage, the COPY command parses the data. Whenever the data can’t be parsed because it is improperly formatted or doesn’t match the data structure, the entire record (or row) will be rejected.

When ERROR_LOG is not used, the COPY command will stop and roll back the transaction upon the first error.

CSV Support

By default, SQream DB’s CSV parser can handle RFC 4180 standard CSVs , but can also be modified to support non-standard CSVs (with multi-character delimiters, unquoted fields, etc).

All CSV files should be prepared according to these recommendations:

• Files are UTF-8 or ASCII encoded

• Field delimiter is an ASCII character or characters

• Record delimiter, also known as a new line separator, is a Unix-style newline (\n), DOS-style newline (\r\n), or Mac style newline (\r).

• Fields are optionally enclosed by double-quotes, or mandatory quoted if they contain one of the following characters:

  • The record delimiter or field delimiter

  • A double quote character

  • A newline

• If a field is quoted, any double quote that appears must be double-quoted (similar to the string literals quoting rules. For example, to encode What are "birds"?, the field should appear as "What are ""birds""?".

  Other modes of escaping are not supported (e.g. 1,"What are \"birds\"?" is not a valid way of escaping CSV values).

Marking Null Markers

NULL values can be marked in two ways in the CSV:

• An explicit null marker. For example, col1,\N,col3

• An empty field delimited by the field delimiter. For example, col1,,col3

Note

If a text field is quoted but contains no content ("") it is considered an empty text field. It is not considered NULL.

Examples

Loading a Standard CSV File

COPY table_name FROM WRAPPER csv_fdw OPTIONS (location = '/tmp/file.csv');

Skipping Faulty Rows

COPY table_name FROM WRAPPER csv_fdw OPTIONS (location = '/tmp/file.csv', continue_on_error = true);

Skipping a Maximum of 100 Faulty Rows

COPY table_name FROM WRAPPER csv_fdw OPTIONS (location = '/tmp/file.csv', continue_on_error = true, error_count = 100);

Loading a Pipe Separated Value (PSV) File

COPY table_name FROM WRAPPER csv_fdw OPTIONS (location = '/tmp/file.psv', delimiter = '|');

Loading a Tab Separated Value (TSV) File

COPY table_name FROM WRAPPER csv_fdw OPTIONS (location = '/tmp/file.tsv', delimiter = '\t');

Loading an ORC File

COPY table_name FROM WRAPPER orc_fdw OPTIONS (location = '/tmp/file.orc');

Loading a Parquet File

COPY table_name FROM WRAPPER parquet_fdw OPTIONS (location = '/tmp/file.parquet');

Loading a JSON File

COPY t FROM WRAPPER json_fdw OPTIONS (location = 'somefile.json');

Loading an AVRO File

COPY t FROM WRAPPER fdw_name OPTIONS ([ copy_from_option [, ...] ]);

Loading a Text File with Non-Printable Delimiters

In the file below, the separator is DC1, which is represented by ASCII 17 decimal or 021 octal.

COPY table_name FROM WRAPPER psv_fdw OPTIONS (location = '/tmp/file.txt', delimiter = E'\021');

Loading a Text File with Multi-Character Delimiters

In the file below, the separator is ^|.

COPY table_name FROM WRAPPER psv_fdw OPTIONS (location = '/tmp/file.txt', delimiter = '^|');

In the file below, the separator is '|. The quote character has to be repeated, as per the literal quoting rules.

COPY table_name FROM WRAPPER psv_fdw OPTIONS (location = '/tmp/file.txt', delimiter = ''''|');

Loading Files with a Header Row

Use OFFSET to skip rows.

Note

When loading multiple files (e.g. with wildcards), this setting affects each file separately.

COPY table_name FROM WRAPPER csv_fdw OPTIONS (location = '/tmp/file.psv', delimiter = '|', offset = 2);

Loading Files Formatted for Windows (\r\n)

COPY table_name FROM WRAPPER csv_fdw OPTIONS (location = '/tmp/file.psv', delimiter = '\r\n');

Loading a File from a Public S3 Bucket

Note

The bucket must be publicly available and objects can be listed

COPY table_name FROM WRAPPER csv_fdw OPTIONS (location = 's3://sqream-demo-data/file.csv', delimiter = '\r\n', offset = 2);

Loading a File From a Google Cloud Platform Bucket

To access a Google Cloud Platform (GCP) Bucket it is required that your environment be authorized.

COPY table_name FROM WRAPPER csv_fdw OPTIONS (location = 'gs://<gcs path>/<gcs_bucket>/*');

Loading a File From Azure

To access Azure it is required that your environment be authorized.

COPY table_name FROM WRAPPER csv_fdw OPTIONS(location = 'azure://sqreamrole.core.windows.net/sqream-demo-data/file.csv');

Loading Files from an Authenticated S3 Bucket

COPY table_name FROM WRAPPER psv_fdw OPTIONS (location = 's3://secret-bucket/*.csv', DELIMITER = '\r\n', OFFSET = 2, AWS_ID = '12345678', AWS_SECRET = 'super_secretive_secret');

Saving Rejected Rows to a File

Note

When loading multiple files (e.g. with wildcards), this error threshold is for the entire transaction.

COPY table_name FROM WRAPPER csv_fdw
                OPTIONS
                (
                location = '/tmp/file.csv'
                ,continue_on_error  = true
                ,error_log  = '/temp/load_error.log'
                );

COPY table_name FROM WRAPPER csv_fdw
                OPTIONS
                (
                location = '/tmp/file.psv'
                ,delimiter '|'
                ,error_log = '/temp/load_error.log' -- Save error log
                ,rejected_data = '/temp/load_rejected.log' -- Only save rejected rows
                ,limit = 100 -- Only load 100 rows
                ,error_count = 5 -- Stop the load if 5 errors reached
                );

Loading CSV Files from a Set of Directories

COPY table_name FROM WRAPPER csv_fdw OPTIONS (location = '/tmp/2019_08_*/*.csv');

Rearranging Destination Columns

When the source of the files does not match the table structure, tell the COPY command what the order of columns should be

COPY table_name (fifth, first, third) FROM WRAPPER csv_fdw OPTIONS (location = '/tmp/*.csv');

Note

Any column not specified will revert to its default value or NULL value if nullable

Loading Non-Standard Dates

If your files contain dates in a format other than ISO8601, you can specify a parsing format to convert them during the import process. This ensures the dates are stored internally as ISO8601 within the database.

In this example, date_col1 and date_col2 in the table are non-standard. date_col3 is mentioned explicitly, but can be left out. Any column that is not specified is assumed to be ISO8601.

COPY my_table (date_col1, date_col2, date_col3) FROM WRAPPER csv_fdw OPTIONS (location = '/tmp/my_data.csv', offset = 2, datetime_format 'DMY');

Loading Specific Columns

Loading specific columns using the COPY FROM command:

• Does not support CSV files

• Requires that the target table columns be nullable

COPY
  new_nba (name, salary)
FROM
WRAPPER
  parquet_fdw
OPTIONS
  (
   LOCATION = '/tmp/nba.parquet'
  );