PEROFFER_D

PEROFFER_D contains the half-hourly period details of daily bids and rebids, to be used in conjunction with DAYOFFER_D. These views provide period varying details such as rate of change up (ROCUP), rate of change down (ROCDOWN) and band quantities (BANDAVAIL from 1 to 10). PEROFFER_D is a child table of DAYOFFER_D.

Deprecation Warning

This table is in the HISTORICAL TABLES package, so is likely deprecated.

Not in Use - discontinued 16/11/2003

Status

PEROFFER and its related views are obsolete. please see BIDPEROFFER views. For a transition period, the PEROFFER views exist, being based on the BIDPEROFFER table.

Source

PEROFFER is obsolete; confidential data was updated for each bid and rebid, with full visibility of rest of market were updated daily as part of next day data.

Column Schema

DUID

Dispatchable Unit identifier

Warning

This column may contain funny characters such as / (slash) or # (hash). This may break hive-style partitioning.

For more information, see the dedicated documentation page.

SQL Type: VARCHAR2(10) Polars Type: pl.Categorical

This column is mandatory, and a primary key.

Example: W/HOE#2

OFFERDATE

Offer date made

Warning

Despite what the name suggests, this is a datetime, not a date.

SQL Type: DATE Polars Type: pl.Datetime()

This column is mandatory, and a primary key.

Example: 2026/01/20 00:05:00

PERIODID

Period identifier

SQL Type: NUMBER(3,0) Polars Type: pl.Int16

This column is mandatory, and a primary key.

SETTLEMENTDATE

Market date starting at 04:00am

Warning

Despite what the name suggests, this is a datetime, not a date.

SQL Type: DATE Polars Type: pl.Datetime()

This column is mandatory, and a primary key.

Example: 2026/01/20 00:05:00

VERSIONNO

Version number of offer

SQL Type: NUMBER(3,0) Polars Type: pl.UInt16

This column is mandatory, and a primary key.

BANDAVAIL1

Availability at price band 1

SQL Type: NUMBER(6,0) Polars Type: pl.Int32

This column is not mandatory.

BANDAVAIL2

Availability at price band 2

SQL Type: NUMBER(6,0) Polars Type: pl.Int32

This column is not mandatory.

BANDAVAIL3

Availability at price band 3

SQL Type: NUMBER(6,0) Polars Type: pl.Int32

This column is not mandatory.

BANDAVAIL4

Availability at price band 4

SQL Type: NUMBER(6,0) Polars Type: pl.Int32

This column is not mandatory.

BANDAVAIL5

Availability at price band 5

SQL Type: NUMBER(6,0) Polars Type: pl.Int32

This column is not mandatory.

BANDAVAIL6

Availability at price band 6

SQL Type: NUMBER(6,0) Polars Type: pl.Int32

This column is not mandatory.

BANDAVAIL7

Availability at price band 7

SQL Type: NUMBER(6,0) Polars Type: pl.Int32

This column is not mandatory.

BANDAVAIL8

Availability at price band 8

SQL Type: NUMBER(6,0) Polars Type: pl.Int32

This column is not mandatory.

BANDAVAIL9

Availability at price band 9

SQL Type: NUMBER(6,0) Polars Type: pl.Int32

This column is not mandatory.

BANDAVAIL10

Availability at price band 10

SQL Type: NUMBER(6,0) Polars Type: pl.Int32

This column is not mandatory.

FIXEDLOAD

Fixed unit output MW. A value of zero means no fixed load so the unit is dispatched according to bid and market (rather than zero fixed load)

SQL Type: NUMBER(12,6) Polars Type: pl.Float64

This column is not mandatory.

LASTCHANGED

Last date and time record changed

For more information, see the dedicated documentation page.

SQL Type: DATE Polars Type: pl.Datetime()

This column is not mandatory.

Example: 2026/01/20 00:05:00

MAXAVAIL

Maximum plant availability

SQL Type: NUMBER(12,6) Polars Type: pl.Float64

This column is not mandatory.

MR_CAPACITY

Mandatory Restriction Offer amount

SQL Type: NUMBER(6,0) Polars Type: pl.Int32

This column is not mandatory.

PASAAVAILABILITY

The physical plant capability including any capability potentially available within 24 hours.

SQL Type: NUMBER(12,0) Polars Type: pl.Int64

This column is not mandatory.

ROCDOWN

MW/Min for lower

SQL Type: NUMBER(6,0) Polars Type: pl.Int32

This column is not mandatory.

ROCUP

MW/min for raise

SQL Type: NUMBER(6,0) Polars Type: pl.Int32

This column is not mandatory.

SELFDISPATCH

Not used

SQL Type: NUMBER(12,6) Polars Type: pl.Float64

This column is unused.

Code Examples

Polars

Casting is enums, categoricals etc is not essential, but may speed up parsing. Swapping int for pl.UInt16, pl.Int32 would also speed up parsing. However some of the datatypes are inferred, so they may be wrong.

This code deduplicates for you. Deduplication is normally only required across multiple months.

This code assumes that all columns are present, which may not be true for older files.

import polars as pl
import polars.selectors as cs

# e.g. "2029/03/15 00:05:00"
dt_s_fmt = "%Y/%m/%d %H:%M:%S"

csv_paths = ["SOMEFILE.CSV", "OTHERFILE.CSV"]

lf = (
    pl.concat(
        [
            pl.scan_csv(
                csv_path,  # must be unzipped beforehand
                skip_rows=1,  # skip the header
                infer_schema=False,  # much faster
            )
            .filter(cs.by_index(0) == "D")  # drop the footer
            .select(~cs.by_index(range(4)))  # drop metadata columns
            for csv_path in csv_paths
        ],
        how="diagonal_relaxed",
    )
    .with_columns(
        pl.col("OFFERDATE", "SETTLEMENTDATE", "LASTCHANGED").str.strptime(
            pl.Datetime, dt_s_fmt
        ),
    )
    .cast(
        {
            "DUID": pl.Categorical,
            "PERIODID": int,  # or pl.Int16
            "VERSIONNO": int,  # or pl.UInt16
            "BANDAVAIL1": int,  # or pl.Int32
            "BANDAVAIL2": int,  # or pl.Int32
            "BANDAVAIL3": int,  # or pl.Int32
            "BANDAVAIL4": int,  # or pl.Int32
            "BANDAVAIL5": int,  # or pl.Int32
            "BANDAVAIL6": int,  # or pl.Int32
            "BANDAVAIL7": int,  # or pl.Int32
            "BANDAVAIL8": int,  # or pl.Int32
            "BANDAVAIL9": int,  # or pl.Int32
            "BANDAVAIL10": int,  # or pl.Int32
            "FIXEDLOAD": pl.Float64,
            "MAXAVAIL": pl.Float64,
            "MR_CAPACITY": int,  # or pl.Int32
            "PASAAVAILABILITY": int,  # or pl.Int64
            "ROCDOWN": int,  # or pl.Int32
            "ROCUP": int,  # or pl.Int32
            "SELFDISPATCH": pl.Float64,
        }
    )
    # Drop deprecated/unused columns
    .drop("SELFDISPATCH")
    # Deduplicate
    # We want one row per ['DUID', 'OFFERDATE', 'PERIODID', 'SETTLEMENTDATE', 'VERSIONNO']
    # Tie-breaker: greatest value of ['LASTCHANGED']
    .sort(["LASTCHANGED"], descending=False)
    .unique(
        subset=["DUID", "OFFERDATE", "PERIODID", "SETTLEMENTDATE", "VERSIONNO"],
        keep="last",
    )
)

Nemosis

This table is not yet available in Nemosis.

Availability

AEMO's documentation states that this table's visibility is "Public". However, it is not available in the public monthly MMSDM archive. AEMO probably call this public because it is available to all market participants over private FTP.

There is a chance that is is still public to non-participants. It may only be available for some months; or (rarely) it may be available in a non-standard location.

Deduplication and PDR Loader Configuration

The primary keys are:

DUID
OFFERDATE
PERIODID
SETTLEMENTDATE
VERSIONNO

PDR Loader configuration does not mention this table, so it is unclear how to choose which row to keep when there are multiple rows for a given set of primary keys.

You should probably take the row with the maximum LASTCHANGED.