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                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

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                                    FORM 8-A

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                FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES
                    PURSUANT TO SECTION 12(b) OR 12(g) OF THE
                         SECURITIES EXCHANGE ACT OF 1934

                             INFORMATICA CORPORATION
                             -----------------------
             (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)


                DELAWARE                              77-0333710
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       (State of Incorporation of       (I.R.S. Employer Identification Number)
              Organization)

                             2100 SEAPORT BOULEVARD
                             REDWOOD CITY, CA 94063
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           (Address of Principal Executive Offices Including Zip Code)

      If this form relates to the registration of a class of securities pursuant
to Section 12(b) of the Exchange Act and is effective pursuant to General
Instruction A.(c), check the following box. [ ]

      If this form relates to the registration of a class of securities
pursuant to Section 12(g) of the Exchange Act and is effective pursuant to
General Instruction A.(d), check the following box.  [X]

      Securities Act registration statement file number to which this form
relates (if applicable): Not applicable.

      Securities to be registered pursuant to Section 12(b) of the Act:

      TITLE OF EACH CLASS                   NAME OF EACH EXCHANGE ON WHICH
      TO BE SO REGISTERED                   EACH CLASS IS TO BE REGISTERED
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             None.
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Securities to be registered pursuant to Section 12(g) of the Act:

                         PREFERRED STOCK PURCHASE RIGHTS
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                                (Title of Class)

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ITEM 1.     DESCRIPTION OF SECURITIES TO BE REGISTERED.

      On October 17, 2001, pursuant to a Preferred Stock Rights Agreement (the
"Rights Agreement") between Informatica Corporation (the "Company") and American
Stock Transfer & Trust Company, as Rights Agent (the "Rights Agent"), the
Company's Board of Directors declared a dividend of one right (a "Right") to
purchase one one-thousandth of a share of the Company's Series A Participating
Preferred Stock ("Series A Preferred") for each outstanding share of Common
Stock, par value $0.001 per share ("Common Shares"), of the Company. The
dividend is payable on November 12, 2001 (the "Record Date") to stockholders of
record as of the close of business on that date. Each Right entitles the
registered holder to purchase from the Company one one-thousandth of a share of
Series A Preferred at an exercise price of $90.00 (the "Purchase Price"),
subject to adjustment as set forth in the Rights Agreement.

      The following summary of the principal terms of the Rights Agreement is a
general description only and is subject to the detailed terms and conditions of
the Rights Agreement. A copy of the Rights Agreement is attached as Exhibit 4.2
to this Registration Statement and is incorporated herein by reference.

RIGHTS EVIDENCED BY COMMON SHARE CERTIFICATES

      The Rights will not be exercisable until the Distribution Date (as defined
below). Certificates for the Rights ("Rights Certificates") will not be sent to
stockholders and the Rights will attach to and trade only together with the
Common Shares. Accordingly, Common Share certificates outstanding on the Record
Date will evidence the Rights related thereto, and Common Share certificates
issued after the Record Date will contain a notation incorporating the Rights
Agreement by reference. Until the Distribution Date (or earlier redemption or
expiration of the Rights), the surrender or transfer of any certificates for
Common Shares outstanding as of the Record Date, even without notation or a copy
of the Summary of Rights being attached thereto, also will constitute the
transfer of the Rights associated with the Common Shares represented by such
certificate.

DISTRIBUTION DATE

      The Rights will separate from the Common Shares, Rights Certificates will
be issued and the Rights will become exercisable upon the earlier of (a) the
tenth day (or such later date as may be determined by the Company's Board of
Directors) after a person or group of affiliated or associated persons (an
"Acquiring Person") has acquired, or obtained the right to acquire, beneficial
ownership of 18% or more of the Common Shares then outstanding, or (b) the tenth
business day (or such later date as may be determined by the Company's Board of
Directors) after a person or group announces a tender or exchange offer, the
consummation of which would result in ownership by a person or group of 18% or
more of the Company's then outstanding Common Shares. The earlier of such dates
is referred to as the "Distribution Date."

ISSUANCE OF RIGHTS CERTIFICATES; EXPIRATION OF RIGHTS

      As soon as practicable following the Distribution Date, a Rights
Certificate will be mailed to holders of record of the Common Shares as of the
close of business on the Distribution Date and this summary alone will evidence
the Rights from and after the Distribution Date. All Common Shares issued after
the Distribution Date will be issued with Rights. The Rights will expire on the
earliest of (i) November 12, 2011, (the "Final Expiration Date"), or (ii)
redemption or exchange of the Rights as described below.

INITIAL EXERCISE OF THE RIGHTS

      Following the Distribution Date, and until one of the further events
described below, holders of the Rights will be entitled to receive, upon
exercise and the payment of the Purchase Price, one one-thousandth of a share of
the Series A Preferred. In the event that the Company does not have sufficient
Series A Preferred available for all Rights to be exercised, or the Board
decides that such action is necessary and not contrary to the interests of
Rights holders, the Company may instead substitute cash, assets or other
securities for the Series A Preferred for which the Rights would have been
exercisable under this provision or as described below.

RIGHT TO BUY COMPANY COMMON SHARES

      Unless the Rights are earlier redeemed, in the event that an Acquiring
Person obtains 18% or more of the Company's then outstanding Common Shares, then
each holder of a Right which has not theretofore been exercised (other than
Rights beneficially owned by the Acquiring Person, which will thereafter be
void) will thereafter have the right to receive, upon exercise, Common Shares
having a value equal to two times the Purchase Price. Rights are not exercisable
following the occurrence of an event as described above until such time as the
Rights are no longer redeemable by the Company as set forth below.

RIGHT TO BUY ACQUIRING COMPANY STOCK

      Similarly, unless the Rights are earlier redeemed, in the event that,
after an Acquiring Person obtains 18% or more of the Company's then outstanding
Common Shares, (i) the Company is acquired in a merger or other business
combination transaction, or (ii) 50% or more of the Company's consolidated
assets or earning power are sold (other than in transactions in the ordinary
course of business), proper provision must be made so that each holder of a
Right which has not theretofore been exercised (other than Rights beneficially
owned by the Acquiring Person, which will thereafter be void) will thereafter
have the right to receive, upon exercise, shares of common stock of the
acquiring company having a value equal to two times the Purchase Price.

EXCHANGE PROVISION

      At any time after an Acquiring Person obtains 18% or more of the Company's
then outstanding Common Shares and prior to the acquisition by such Acquiring
Person of 50% or more of the Company's outstanding Common Shares, the Board of
Directors of the Company may exchange the Rights (other than Rights owned by the
Acquiring Person), in whole or in part, at an exchange ratio of one Common Share
per Right.

REDEMPTION

      At any time on or prior to the Close of Business on the earlier of (i) the
fifth day following the attainment of 18% or more of the Company's then
outstanding Common Shares by an Acquiring Person (or such later date as may be
determined by action of the Company's Board of Directors and publicly announced
by the Company), or (ii) the Final Expiration Date, the Company may redeem the
Rights in whole, but not in part, at a price of $0.001 per Right.

ADJUSTMENTS TO PREVENT DILUTION

      The Purchase Price payable, the number of Rights, and the number of Series
A Preferred or Common Shares or other securities or property issuable upon
exercise of the Rights are subject to adjustment from time


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to time in connection with the dilutive issuances by the Company as set forth in
the Rights Agreement. With certain exceptions, no adjustment in the Purchase
Price will be required until cumulative adjustments require an adjustment of at
least 1% in such Purchase Price.

CASH PAID INSTEAD OF ISSUING FRACTIONAL SHARES

      No fractional Common Shares will be issued upon exercise of a Right and,
in lieu thereof, an adjustment in cash will be made based on the market price of
the Common Shares on the last trading date prior to the date of exercise.

NO STOCKHOLDERS' RIGHTS PRIOR TO EXERCISE

      Until a Right is exercised, the holder thereof, as such, will have no
rights as a stockholder of the Company (other than any rights resulting from
such holder's ownership of Common Shares), including, without limitation, the
right to vote or to receive dividends.

AMENDMENT OF RIGHTS AGREEMENT

      The terms of the Rights and the Rights Agreement may be amended in any
respect without the consent of the Rights holders on or prior to the
Distribution Date; thereafter, the terms of the Rights and the Rights Agreement
may be amended without the consent of the Rights holders in order to cure any
ambiguities or to make changes which do not adversely affect the interests of
Rights holders (other than the Acquiring Person).

RIGHTS AND PREFERENCES OF THE SERIES A PREFERRED

      Each one one-thousandth of a share of Series A Preferred has rights and
preferences substantially equivalent to those of one Common Share.

NO VOTING RIGHTS

      Rights will not have any voting rights.

THREE-YEAR INDEPENDENT DIRECTOR EVALUATION

      The Rights Agreement includes a "TIDE" (Three-Year Independent Director
Evaluation) provision. Under the TIDE provision, a Stockholder Rights Plan
Committee composed of independent members of the Board of Directors will review
the Rights Plan periodically, but at least every three years. This committee
will communicate its conclusions to the full Board of Directors after each
review, including any recommendation as to whether the Rights Plan should be
modified or the Rights should be redeemed.

CERTAIN ANTI-TAKEOVER EFFECTS

      The Rights approved by the Board are designed to protect and maximize the
value of the outstanding equity interests in the Company in the event of an
unsolicited attempt by an acquirer to take over the Company in a manner or on
terms not approved by the Board of Directors. Takeover attempts frequently
include coercive tactics to deprive the Company's Board of Directors and its
stockholders of any real opportunity to determine the destiny of the Company.
The Rights have been declared by the Board in order to deter such tactics,
including a gradual accumulation of shares in the open market of an 18% or
greater position to be followed by a merger or a partial or two-tier tender
offer that does not treat all stockholders


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equally. These tactics unfairly pressure stockholders, squeeze them out of their
investment without giving them any real choice and deprive them of the full
value of their shares.

      The Rights are not intended to prevent a takeover of the Company and will
not do so. Subject to the restrictions described above, the Rights may be
redeemed by the Company at $0.001 per Right at any time prior to the
Distribution Date. Accordingly, the Rights should not interfere with any merger
or business combination approved by the Board of Directors.

      However, the Rights may have the effect of rendering more difficult or
discouraging an acquisition of the Company deemed undesirable by the Board of
Directors. The Rights may cause substantial dilution to a person or group that
attempts to acquire the Company on terms or in a manner not approved by the
Company's Board of Directors, except pursuant to an offer conditioned upon the
negation, purchase or redemption of the Rights.

      Issuance of the Rights does not in any way weaken the financial strength
of the Company or interfere with its business plans. The issuance of the Rights
themselves has no dilutive effect, will not affect reported earnings per share,
should not be taxable to the Company or to its stockholders, and will not change
the way in which the Company's shares are presently traded. The Company's Board
of Directors believes that the Rights represent a sound and reasonable means of
addressing the complex issues of corporate policy created by the current
takeover environment.

ITEM 2.     EXHIBITS

      3.2   Amended and Restated Certificate of Incorporation of Informatica
            Corporation(1)
      3.3   By-laws, as amended, of Informatica Corporation (1)
      3.4   Certificate of Amendment to the Company's Amended and Restated
            Certificate of Incorporation to increase the aggregate number of
            shares of the Company's common stock authorized for issuance from
            100,000,000 to 200,000,000 shares (2)
      3.5   Certificate of Designation of Rights, Preferences and Privileges of
            Series A Participating Preferred Stock of Informatica Corporation
      4.2   Preferred Stock Rights Agreement, dated as of October 17, 2001,
            between Informatica Corporation and American Stock Transfer & Trust
            Company


      (1) Incorporated by reference to the identically numbered Exhibit to
Amendment No. 1 of the Company's Registration Statement on Form S-1/A
(Commission File No. 333-72677), which was filed on April 8, 1999.

      (2) Incorporated by reference to the identically numbered Exhibit to the
Company's Quarterly Report on Form 10-Q filed with the Securities and Exchange
Commission on August 14, 2000.


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                                    SIGNATURE

      Pursuant to the requirements of Section 12 of the Securities Exchange Act
of 1934, the Registrant has duly caused this Registration Statement to be signed
on its behalf by the undersigned, thereto duly authorized.



Date: November 6, 2001                    Informatica Corporation



                                          By:   /s/ Earl E. Fry
                                                --------------------------------
                                                Earl E. Fry
                                                Chief Financial Officer


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                                  EXHIBIT INDEX


      3.2   Amended and Restated Certificate of Incorporation of Informatica
            Corporation(1)
      3.3   By-laws, as amended, of Informatica Corporation (1)
      3.4   Certificate of Amendment to the Company's Amended and Restated
            Certificate of Incorporation to increase the aggregate number of
            shares of the Company's common stock authorized for issuance from
            100,000,000 to 200,000,000 shares (2)
      3.5   Certificate of Designation of Rights, Preferences and Privileges of
            Series A Participating Preferred Stock of Informatica Corporation
      4.2   Preferred Stock Rights Agreement, dated as of October 17, 2001,
            between Informatica Corporation and American Stock Transfer & Trust
            Company


      (1) Incorporated by reference to the identically numbered Exhibit to
Amendment No. 1 of the Company's Registration Statement on Form S-1/A
(Commission File No. 333-72677), which was filed on April 8, 1999.

      (2) Incorporated by reference to the identically numbered Exhibit to the
Company's Quarterly Report on Form 10-Q filed with the Securities and Exchange
Commission on August 14, 2000.

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