Primitive Data Types
Source | Destinations | ||||
---|---|---|---|---|---|
PostgreSQL | PostgreSQL | BigQuery | Snowflake | Clickhouse | ElasticSearch |
smallint | smallint | INTEGER | INTEGER | Int16 | long |
integer | integer | INTEGER | INTEGER | Int32 | long |
bigint | bigint | INTEGER | INTEGER | Int64 | long |
float4 | float4 | FLOAT | FLOAT | Float32 | float |
double precision | double precision | FLOAT | FLOAT | Float64 | float |
boolean | bool | BOOLEAN | BOOLEAN | Bool | boolean |
"char" | CHAR | STRING | STRING | FixedString(1) | text |
varchar | varchar | STRING | STRING | String | text |
date | date | DATE | DATE | Date | date |
json | json | JSON | VARIANT | String | unnested subdocument |
jsonb | jsonb | JSON | VARIANT | String | unnested subdocument |
numeric | numeric | BIGNUMERIC | NUMBER | Decimal | text |
text | text | STRING | STRING | String | text |
timestamp | timestamp | TIMESTAMP | TIMESTAMP_NTZ | DateTime64(6) | date |
timestamp with time zone | timestamp with time zone | TIMESTAMP | TIMESTAMP_TZ | DateTime64(6) | date |
time | time | TIME | TIME | String | date |
bit | bit | BYTES | BINARY | String | text |
bit varying | varbit | BYTES | BINARY | String | text |
bytea | bytea | BYTES | BINARY | String | text |
geography | geography | GEOGRAPHY | GEOGRAPHY | String | Coming soon! |
geometry | geometry | GEOGRAPHY | GEOMETRY | String | Coming soon! |
inet | inet | STRING | STRING | String | text |
macaddr | macaddr | STRING | STRING | String | text |
cidr | cidr | STRING | STRING | String | text |
hstore | hstore | JSON | VARIANT | String | Coming soon! |
uuid | uuid | STRING | STRING | uuid | Coming soon! |
Array Data Types
Source | Destinations | |||
---|---|---|---|---|
PostgreSQL Type | PostgreSQL | BigQuery | Snowflake | Clickhouse |
ARRAY<INT2> | ARRAY<INT2> | ARRAY<INT> | VARIANT | Array<Int16> |
ARRAY<INT4> | ARRAY<INT4> | ARRAY<INT> | VARIANT | Array<Int32> |
ARRAY<INT8> | ARRAY<INT8> | ARRAY<INT> | VARIANT | Array<Int64> |
ARRAY<FLOAT4> | ARRAY<FLOAT4> | ARRAY<FLOAT> | VARIANT | Array<Float32> |
ARRAY<DOUBLE PRECISION> | ARRAY<DOUBLE PRECISION> | ARRAY<DOUBLE PRECISION> | VARIANT | Array<Float64> |
ARRAY<BOOL> | ARRAY<BOOL> | ARRAY<BOOL> | VARIANT | Array<Bool> |
ARRAY<VARCHAR> | ARRAY<VARCHAR> | ARRAY<STRING> | VARIANT | Array<String> |
ARRAY<TEXT> | ARRAY<TEXT> | ARRAY<STRING> | VARIANT | Array<String> |
ARRAY<DATE> | ARRAY<DATE> | ARRAY<DATE> | VARIANT | String |
ARRAY<TIMESTAMP> | ARRAY<TIMESTAMP> | ARRAY<TIMESTAMP> | VARIANT | String |
ARRAY<TIMESTAMPTZ> | ARRAY<TIMESTAMPTZ> | ARRAY<TIMESTAMP> | VARIANT | String |
Design Choices
We recognise that there are various approaches to handling certain data types. Here are some decisions we’ve taken for PeerDB.Numeric Type
For Snowflake, we map PostgreSQL’snumeric
type as follows:
numeric
with no specified precision and scale is mapped toNUMBER(38,20)
.numeric
with precision OR scale which is beyond 38 and 37 is mapped toNUMBER(38, 20)
.numeric
with precision AND scale within the above limits is mapped toNUMBER(precision, scale)
.
numeric
type as follows:
numeric
with no specified precision and scale is mapped toBIGNUMERIC(38,20)
.numeric
with precision OR scale which is beyond 38 and 37 respectively, is mapped toBIGNUMERIC(38, 20)
.numeric
with precision AND scale within the above limits is mapped toBIGNUMERIC(precision, scale)
.
numeric
type as follows:
numeric
with no specified precision and scale is mapped toDecimal(76,38)
.- Values with more than 38 fractional digits will be truncated to 38 fractional digits and log a warning.
- Values with more than 38 integer digits will be set to 0 and log a warning.
numeric
with precision OR scale which is beyond 76 and 38 respectively, is mapped toDecimal(76,38)
.numeric
with precision AND scale within the above limits is mapped toDecimal(precision, scale)
.
Geospatial Data
PeerDB detects invalid shapes (for example, alinestring
with only one point) among PostGIS values it pulls, and writes them as null on the destination.
We keep a log of this data and it can be retrieved if needed.
Valid geospatial data is written on BigQuery and Snowflake in Well-Known Text (WKT)
format,
while to PostgreSQL destinations it is written as it is received.
HStore Data
PeerDB writesHSTORE
data as JSON
on BigQuery. All intricaces of the HSTORE
data type are preserved, such as:
NULL
values. Example:'"a"=>NULL'
will be written as{"a":null}
- Empty keys. Example:
'""=>1'
will be written as{"":1}
- Overriding duplicate key values. Example:
'"a"=>"1", "a"=>"2"'
will be written as{"a":2}
VARIANT
data type, although it is
formatted as a JSON
and can be queried as such - snowflake_hstore_column:key
.
Nulls in BigQuery Arrays
PeerDB removesnull
values from BigQuery arrays. This is because BigQuery does not support null
values in arrays during their insertion.