How many records can spss handle

Fortunately, you as the user do not normally need to interact with the underlying integers, and you can type in data values for date and time variables using normal date-time conventions. However, dates and times can be written using a number of different conventions, so we need a way to tell SPSS how to read and parse our date strings. That's where the concept of date formats comes in.

When reading data containing dates or using certain date-time functions, we need to tell SPSS which date format to use, so that it knows how to correctly parse the components of the input string.

There are different formats for different variable types, and each format in SPSS has a unique name. Your choice of format will depend on the whether or not the input is a date or a duration, as well as the time units included in the data value, the order of the units e.

In the "Date-Time Unit" column, the date components are represented using the following codes:. In the "general form" column, the name of the format appears first, followed by the letter w or w.

The letter w denotes the number of "columns" typically the number of characters in the input string , and the letter d represents the number of decimal places, if present. You will replace these with the appropriate number to use for the width of the date.

You'll see an example of how date-time formats are used in the example of converting a string variable to a date variable. In the "Duration Unit" column, the time components are represented using the following codes:. Just as with date formats, the "general form" of the format name contains w or w.

Notice how in the column of examples, SPSS took the same underlying data and automatically converted the time units based on the formats we chose.

This is one of the benefits of using date-time variables to represent dates and durations: they give us the option to change how how the data is displayed without needing to do the conversion arithmetic ourselves.

Source In previous versions, these date formats would not recognize dates that did not contain the appropriate delimiters. Click OK. If you try to select a format that includes additional or different information, the change in format may fail and blank out the data. Then, you can repeat this process to select the new format in which you want the dates to appear. Do not select a format that does not match the current format of the values.

Now click the Data View tab to view your data; your dates should now appear in the format you selected. Note : If you select a new format that includes space for information that does not actually appear in your dataset, it will appear as 0s in the data. For example, if your data only includes information about the month, day, and year, and you select a format that also includes space for the hour, minute, and second, values will appear like this one: JAN When writing dates, it's common to see individuals abbreviate the year to two digits, especially in contexts where the century is "obvious" to the reader.

This is fine when making notes to yourself, but when you're trying to compile data for analysis, this can be hugely problematic, especially when working with data that covers a large time range, or is very far in the past. In general, we recommend always using four-digit years when entering data for dates. But sometimes you may not be in control of how the data was entered -- you may receive or request a dataset where the dates only used two-digit years.

For these situations, it's important to know how to appropriately define the century range in SPSS. If you didn't have any other context clues, you'd probably base your guess on the current year The default century range in SPSS is based on the current year: it will start the range at 69 years prior to the current year and end the range at 30 years after the current year source. Why does the century range matter?

If you are going to compute elapsed time, or want to use your date variables as a predictor in a model, you can imagine how problematic it would be if one of the dates was off by years! For this reason, it's critical that you specify the appropriate century range when working with dates containing two-digit years. By default, Automatic will be selected and two-digit years will be understood to fall in the range of the current year minus 69 to the current year plus You can change the century range by clicking Custom , which will allow you to input a new beginning year and the end year will be imputed for you.

When you are finished, click Apply , and then click OK. The yyyy to the right of the equals sign is the desired beginning year for the century range. SPSS conveniently includes a Date and Time Wizard that can assist with transformations and calculations that involve date and time variables.

Although there are many options, it is useful to begin by first reading about how dates and times are represented in SPSS. We have selected this option Learn how dates and times are represented in the Date and Time Wizard window depicted above. Now, click Next. You will see the following window. When you are finished reading, click Back to return to the main Date and Time Wizard menu. Note that the Date and Time Wizard can assist with many tasks related to dates and time, including:.

We will not cover each of these options in this tutorial, but we will cover one of the most common uses for the Date and Time Wizard: calculations involving dates and times. If you have datetime variables in a text or CSV file, SPSS will often read those variables in as string or character variables, instead of treating them as actual dates. In order to have those variables correctly recognized, you'll need to convert them from string to date.

In the sample dataset, the variable enrolldate date of college enrollment contains dates in the form dd-mmm-yyyy , but was read into the dataset as a string variable. Let's convert that variable from a string to a numeric date. Sometimes you may need to calculate the length of time that has passed between two points in time.

Any unit of time can be used. This means that you can calculate how many years, months, days, hours, minutes, or even seconds old each person is. Before we can perform a calculation with dates and times, we first need to make sure that our dataset has at least two variables that represent time points.

We can compute the age that each person was when they enrolled in college using these two time points. A Variables : Lists all of the available date and time variables in your dataset.

B Date1 : The right half of the dialog box is where we will specify which variables to use, and how to set up the calculation. C Unit : The unit of time to use for the variable you are creating. In this example, select Years from the Unit list. D Result Treatment: Specify how to treat the values of the variable that will be calculated.

You can choose to truncate to integer , round to integer , or retain fractional part. Truncate to integer means dropping the fractional part e. Round to integer bumps the number to the nearest integer e. Log in. For a better experience, please enable JavaScript in your browser before proceeding. How many data rows can SPSS handle? FrankC New Member May 18, In a few weeks an internet survey will hopefully start that should get a response rate of somewhere between 2 and 6 thousand people.

I'm assuming the latter for now, just to be sure. The MySQL table will be split into subtables, but the biggest subtable might still have some records. We are to do a multiple regression analysis of a couple of variables. Can it handle that many records? If not, what would be the maximum number of data rows it can handle?

I searched its Help section but couldn't find the answer there.